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ভূমিকা

ক্রিপ্টোকারেন্সি বাজারে, ট্রেডিং সুযোগগুলি ক্ষণস্থায়ী, বিশেষ করে উচ্চ-ফলনশীল আরবিট্রেজ উইন্ডো, যা প্রায়শই খুব অল্প সময়ের জন্য স্থায়ী হয়। আপনি যদি শুধুমাত্র ম্যানুয়াল ট্রেডিংয়ের উপর নির্ভর করেন, তাহলে বাজারের সাথে তাল মিলিয়ে চলা প্রায়শই কঠিন হয়ে পড়ে। অতএব, পেন্ডিং অর্ডার ট্রেডিং ট্রেডিং দক্ষতা উন্নত করার একটি গুরুত্বপূর্ণ উপায় হয়ে ওঠে।

এই প্রবন্ধটি Xiaocao-এর প্রবন্ধের ধারণার উপর ভিত্তি করে লেখা। এটি FMZ প্ল্যাটফর্মে Curve.fi-এর ট্রেডিং পুল অর্ডার কৌশল পুনর্গঠন করে এবং FMZ প্ল্যাটফর্মের মাধ্যমে একই প্রভাব কীভাবে অর্জন করা যায় তা উপস্থাপন করে। একই সাথে, প্রোগ্রাম্যাটিক ট্রেডিং প্রক্রিয়ায় নিরাপত্তা এবং সুবিধা উভয়ই নিশ্চিত করার জন্য ব্যক্তিগত কী সুরক্ষা প্রকল্পটিও বিস্তারিতভাবে আলোচনা করা হবে।

কৌশলটি জাভাস্ক্রিপ্টে লেখা এবং FMZ প্ল্যাটফর্মের web3 eth এক্সচেঞ্জ অবজেক্ট ব্যবহার করে।

নকশা অনুসারে নিরাপত্তা

প্রবন্ধের উপর ভিত্তি করে「বিকেন্দ্রীভূত এক্সচেঞ্জে অর্ডার প্লেসমেন্ট কীভাবে বাস্তবায়ন করবেন - কার্ভকে উদাহরণ হিসেবে নিলে」নিরাপত্তা নকশায়, আমরা একই রকম AES এনক্রিপশন পদ্ধতি ব্যবহার করি। আমরা ডেটা এনক্রিপ্ট করার জন্য একটি পাসওয়ার্ড এবং একটি গণনা ব্যবহার করি।

• পাসওয়ার্ড: পাসওয়ার্ড, sha256 দিয়ে হ্যাশ করা।
• গণনা: গণনা করুন, এনক্রিপশনে অংশগ্রহণের জন্য টাইমস্ট্যাম্পটিকে এলোমেলো গণনা হিসেবে ব্যবহার করুন।

১. অফলাইনে প্রাইভেট কী এনক্রিপ্ট করুন, প্রাইভেট কী এনক্রিপ্ট করতে “পাসওয়ার্ড” এবং “গণনা” ব্যবহার করুন এবং একটি এনক্রিপ্ট করা গোপন কী পান। 2. FMZ প্ল্যাটফর্মে এনক্রিপ্ট করা কী, পাসওয়ার্ড, গণনা ইত্যাদি কনফিগার করুন এবং পলিসি ইন্টারফেস প্যারামিটার “এনক্রিপ্টেড স্ট্রিং” নিয়ন্ত্রণ ব্যবহার করুন। নিয়ন্ত্রণে প্রবেশ করা বিষয়বস্তু এনক্রিপ্ট করা হবে এবং প্ল্যাটফর্মে রেকর্ড করা কনফিগারেশন তথ্য নিয়ন্ত্রণের প্লেইন টেক্সট সামগ্রী নয়। ৩. যখন কৌশলটি চলমান থাকে, তখন কাস্টোডিয়ান তথ্যটি ডিক্রিপ্ট করতে পারেন এবং গোপন কী লোড করতে পারেন (গোপন কী লোড করার পরে, সমস্ত সম্পর্কিত ভেরিয়েবল রিসেট করা হবে)।

// 加密/解密方式
function cryptoKey(type, data, passWord, count) {
    // 加载加密库
    eval(HttpQuery("https://cdnjs.cloudflare.com/ajax/libs/aes-js/3.1.2/index.min.js"))

    // sha256 密码
    var hash = Encode("sha256", "string", "hex", passWord).substring(0, 32)

    if (type == "encrypt") {
        var key = aesjs.utils.utf8.toBytes(hash.substring(0, 32))
        var counter = new aesjs.Counter(count)
        var textBytes = aesjs.utils.utf8.toBytes(data)
        var aesCtr = new aesjs.ModeOfOperation.ctr(key, counter)
        var encryptedBytes = aesCtr.encrypt(textBytes)
        var encryptedHex = aesjs.utils.hex.fromBytes(encryptedBytes)
        return encryptedHex
    } else if (type == "decrypt") {
        var key = aesjs.utils.utf8.toBytes(hash.substring(0, 32))
        var counter = new aesjs.Counter(count)
        var aesCtrDecrypt = new aesjs.ModeOfOperation.ctr(key, counter)
        const decryptedBytes = aesCtrDecrypt.decrypt(aesjs.utils.hex.toBytes(data))
        const decryptedText = aesjs.utils.utf8.fromBytes(decryptedBytes)        
        return decryptedText
    } else {
        throw "function cryptoKey(), param 'type' not support"
    }
}

ওয়েব৩ এক্সচেঞ্জ অবজেক্ট কনফিগার করুন

https://www.fmz.com/m/platforms/add

অনলাইনে অনেক ইথেরিয়াম নোড পাওয়া যায়, সাধারণত ব্যবহৃত নোডগুলি হল:

• https://auth.quicknode.com/
• https://www.infura.io/

আপনি নিজের ঠিকানা তৈরি করার জন্য আবেদন করতে পারেন এবং তারপর এটি ব্যবহারের জন্য কনফিগার করতে পারেন। আমি এখানে বিস্তারিত আলোচনা করব না। আপনি ইচ্ছামত গুরুত্বপূর্ণ তথ্য পূরণ করতে পারেন। আমরা এটিকে গতিশীলভাবে লোড করার পরিকল্পনা করছি, তাই এখানে এটি কনফিগার করার কোনও মানে হয় না।

    exchange.IO("key", cryptoKey(descCryptoType[cryptoType], keyData, password, count))
    walletAddress = exchange.IO("address")
    Log("载入秘钥，钱包地址：", walletAddress)

ডিক্রিপশনের পরে প্রাইভেট কী লোড এবং আপডেট করতে প্ল্যাটফর্ম দ্বারা এনক্যাপসুলেট করা exchange.IO(“key”, …) ফাংশনটি ব্যবহার করুন।

ABI নিবন্ধন করুন

নিরাপত্তা সমস্যা সমাধানের পর, পরবর্তী ধাপ হল ইথেরিয়াম স্মার্ট চুক্তিতে কিছু ক্রিয়াকলাপ সম্পাদন করা। Xiaocao দ্বারা উল্লিখিত Curve.fi DEX অনুসারে, আমরা সহজেই এই dAppটি অনলাইনে খুঁজে পেতে পারি:

https://curve.fi/dex/ethereum/pools/factory-stable-ng-102/deposit/

sDAI/sUSDe এক্সচেঞ্জ পুল পৃষ্ঠায়, আপনি এক্সচেঞ্জ পুল চুক্তির ঠিকানা খুঁজে পেতে পারেন এবং চুক্তিটি পর্যবেক্ষণ করতে পারেন। আমরা যে পদ্ধতিগুলি ব্যবহার করতে পারি তা হল:

• কয়েন: পুলে লেনদেনে অংশগ্রহণকারী টোকেনের চুক্তির ঠিকানা পান
• get_dy: পুলে বর্তমান বিনিময় পরিমাণ গণনা করুন।
• বিনিময়: বিনিময় সম্পাদন করুন।

এই পদ্ধতিগুলি কল করার জন্য, আপনাকে প্রথমে পুল চুক্তির ABI নিবন্ধন করতে হবে। আমি ব্যবহৃত পদ্ধতিগুলি ফিল্টার করিনি, বরং সম্পূর্ণ ABI সরাসরি কপি এবং পেস্ট করেছি এবং তারপর এটি নিবন্ধন করেছি:

    // sDAI/sUSDe 池合约地址和ABI
    var poolAddress = "0x167478921b907422F8E88B43C4Af2B8BEa278d3A"
    // 合约ABI
    var poolABI = `[{"name":"Transfer","inputs":[{"name":"sender","type":"address","indexed":true},{"name":"receiver","type":"address","indexed":true},{"name":"value","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"Approval","inputs":[{"name":"owner","type":"address","indexed":true},{"name":"spender","type":"address","indexed":true},{"name":"value","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"TokenExchange","inputs":[{"name":"buyer","type":"address","indexed":true},{"name":"sold_id","type":"int128","indexed":false},{"name":"tokens_sold","type":"uint256","indexed":false},{"name":"bought_id","type":"int128","indexed":false},{"name":"tokens_bought","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"TokenExchangeUnderlying","inputs":[{"name":"buyer","type":"address","indexed":true},{"name":"sold_id","type":"int128","indexed":false},{"name":"tokens_sold","type":"uint256","indexed":false},{"name":"bought_id","type":"int128","indexed":false},{"name":"tokens_bought","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"AddLiquidity","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"invariant","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidity","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidityOne","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_id","type":"int128","indexed":false},{"name":"token_amount","type":"uint256","indexed":false},{"name":"coin_amount","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidityImbalance","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"invariant","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RampA","inputs":[{"name":"old_A","type":"uint256","indexed":false},{"name":"new_A","type":"uint256","indexed":false},{"name":"initial_time","type":"uint256","indexed":false},{"name":"future_time","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"StopRampA","inputs":[{"name":"A","type":"uint256","indexed":false},{"name":"t","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"ApplyNewFee","inputs":[{"name":"fee","type":"uint256","indexed":false},{"name":"offpeg_fee_multiplier","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"SetNewMATime","inputs":[{"name":"ma_exp_time","type":"uint256","indexed":false},{"name":"D_ma_time","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"stateMutability":"nonpayable","type":"constructor","inputs":[{"name":"_name","type":"string"},{"name":"_symbol","type":"string"},{"name":"_A","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_offpeg_fee_multiplier","type":"uint256"},{"name":"_ma_exp_time","type":"uint256"},{"name":"_coins","type":"address[]"},{"name":"_rate_multipliers","type":"uint256[]"},{"name":"_asset_types","type":"uint8[]"},{"name":"_method_ids","type":"bytes4[]"},{"name":"_oracles","type":"address[]"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"exchange","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange_received","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange_received","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"add_liquidity","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_min_mint_amount","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"add_liquidity","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_min_mint_amount","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"},{"name":"_min_received","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"},{"name":"_min_received","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_imbalance","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_max_burn_amount","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_imbalance","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_max_burn_amount","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"},{"name":"_receiver","type":"address"},{"name":"_claim_admin_fees","type":"bool"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"withdraw_admin_fees","inputs":[],"outputs":[]},{"stateMutability":"view","type":"function","name":"last_price","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ema_price","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_p","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"price_oracle","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"D_oracle","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"transfer","inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"transferFrom","inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"approve","inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"permit","inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_deadline","type":"uint256"},{"name":"_v","type":"uint8"},{"name":"_r","type":"bytes32"},{"name":"_s","type":"bytes32"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"view","type":"function","name":"DOMAIN_SEPARATOR","inputs":[],"outputs":[{"name":"","type":"bytes32"}]},{"stateMutability":"view","type":"function","name":"get_dx","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_dy","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"dx","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"calc_withdraw_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"totalSupply","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_virtual_price","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"calc_token_amount","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_is_deposit","type":"bool"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"A_precise","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"balances","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_balances","inputs":[],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"view","type":"function","name":"stored_rates","inputs":[],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"view","type":"function","name":"dynamic_fee","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"ramp_A","inputs":[{"name":"_future_A","type":"uint256"},{"name":"_future_time","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"stop_ramp_A","inputs":[],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_new_fee","inputs":[{"name":"_new_fee","type":"uint256"},{"name":"_new_offpeg_fee_multiplier","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_ma_exp_time","inputs":[{"name":"_ma_exp_time","type":"uint256"},{"name":"_D_ma_time","type":"uint256"}],"outputs":[]},{"stateMutability":"view","type":"function","name":"N_COINS","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"coins","inputs":[{"name":"arg0","type":"uint256"}],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"fee","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"offpeg_fee_multiplier","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"admin_fee","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"initial_A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"future_A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"initial_A_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"future_A_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"admin_balances","inputs":[{"name":"arg0","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ma_exp_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"D_ma_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ma_last_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"name","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"symbol","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"decimals","inputs":[],"outputs":[{"name":"","type":"uint8"}]},{"stateMutability":"view","type":"function","name":"version","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"balanceOf","inputs":[{"name":"arg0","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"allowance","inputs":[{"name":"arg0","type":"address"},{"name":"arg1","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"nonces","inputs":[{"name":"arg0","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"salt","inputs":[],"outputs":[{"name":"","type":"bytes32"}]}]`

    // 注册ABI
    exchange.IO("abi", poolAddress, poolABI)

ওয়ালেট ব্যালেন্স এবং টোকেন ব্যালেন্স পড়ুন

ওয়ালেট টোকেন ব্যালেন্স পড়া, টোকেন নির্ভুলতা, টোকেন নাম ইত্যাদি ERC20 চুক্তির সমস্ত পদ্ধতি এবং ডিফল্টরূপে নিবন্ধিত।

    var token0Name = exchange.IO("api", token0Address, "symbol")
    var token1Name = exchange.IO("api", token1Address, "symbol")
    var token0Decimals = exchange.IO("api", token0Address, "decimals")
    var token1Decimals = exchange.IO("api", token1Address, "decimals")

    var sDAI_Balance = exchange.IO("api", sDAI["address"], "balanceOf", walletAddress)
    var sUSDe_Balance = exchange.IO("api", sUSDe["address"], "balanceOf", walletAddress)

এক্সচেঞ্জ পুল পর্যবেক্ষণ

function getBuyProfit(poolAddress, sDAI, sUSDe, amountIn, entryPriceForDAI) {    
    var data = exchange.IO("api", poolAddress, "get_dy", sDAI["idx"], sUSDe["idx"], toInnerAmount(amountIn, sDAI["decimals"]))
    Log("get_dy:", data)
    var amountOut = toAmount(data, sUSDe["decimals"])
    if (!amountOut) {
        return null
    }
    
    var profit = amountOut - entryPriceForDAI * amountIn  
    return {"profit": profit, "amountOut": amountOut, "sDAI_sUSDe_price": amountOut / amountIn}
}

ট্রিগার শর্তগুলি নিম্নরূপ ডিজাইন করা হয়েছে:

    if (profit > 1000 && sDAI_Balance > amountIn) {
        Log("达到兑换条件，开始执行 sDAI -> sUSDe 兑换交易...")
        /* 兑换操作代码仅为教学演示，该功能请慎用，请先测试 
        executeTrade(poolAddress, sDAI, sUSDe, amountIn, 0.999*amountOut)
        */
    }

বিনিময় কার্যক্রম তখনই সম্পাদিত হতে পারে যখন বর্তমান বিনিময় পরিমাণ ১০০০ এর বেশি লাভ পূরণ করে এবং ওয়ালেটে পর্যাপ্ত sDAI টোকেন থাকে।

এক্সচেঞ্জ অপারেশন

function executeTrade(poolAddress, tokenIn, tokenOut, amountIn, minOutAmount) {
    // exchange : i , j , _dx , _min_dy
    var swapTx = exchange.IO("api", poolAddress, "exchange", tokenIn["idx"], tokenOut["idx"], toInnerAmount(amountIn, tokenIn["decimals"]), toInnerAmount(minOutAmount, tokenOut["decimals"]))
    if (swapTx) {
        while (true) {
            Sleep(1000 * 3)
            let info = e.IO("api", "eth", "eth_getTransactionReceipt", swapTx)
            if (info && info.gasUsed) {
                return true
            }
            Log('Transaction not yet mined', swapTx)
        }
    }

    return false 
}

সম্পূর্ণ কৌশল কোড

function toAmount(s, decimals) {
    return Number((BigDecimal(BigInt(s)) / BigDecimal(Math.pow(10, decimals))).toString())
}

function toInnerAmount(n, decimals) {
    return (BigDecimal(n) * BigDecimal(Math.pow(10, decimals))).toFixed(0)
}

function getBuyProfit(poolAddress, sDAI, sUSDe, amountIn, entryPriceForDAI) {    
    var data = exchange.IO("api", poolAddress, "get_dy", sDAI["idx"], sUSDe["idx"], toInnerAmount(amountIn, sDAI["decimals"]))
    var amountOut = toAmount(data, sUSDe["decimals"])
    if (!amountOut) {
        return null
    }
    
    var profit = amountOut - entryPriceForDAI * amountIn  
    return {"profit": profit, "amountOut": amountOut, "sDAI_sUSDe_price": amountOut / amountIn}
}

function executeTrade(poolAddress, tokenIn, tokenOut, amountIn, minOutAmount) {
    // exchange : i , j , _dx , _min_dy
    var swapTx = exchange.IO("api", poolAddress, "exchange", tokenIn["idx"], tokenOut["idx"], toInnerAmount(amountIn, tokenIn["decimals"]), toInnerAmount(minOutAmount, tokenOut["decimals"]))
    if (swapTx) {
        while (true) {
            Sleep(1000 * 3)
            let info = e.IO("api", "eth", "eth_getTransactionReceipt", swapTx)
            if (info && info.gasUsed) {
                return true
            }
            Log('Transaction not yet mined', swapTx)
        }
    }

    return false 
}

// 加密/解密方式
function cryptoKey(type, data, passWord, count) {
    // 加载加密库
    eval(HttpQuery("https://cdnjs.cloudflare.com/ajax/libs/aes-js/3.1.2/index.min.js"))

    // sha256 密码
    var hash = Encode("sha256", "string", "hex", passWord).substring(0, 32)

    if (type == "encrypt") {
        var key = aesjs.utils.utf8.toBytes(hash.substring(0, 32))
        var counter = new aesjs.Counter(count)
        var textBytes = aesjs.utils.utf8.toBytes(data)
        var aesCtr = new aesjs.ModeOfOperation.ctr(key, counter)
        var encryptedBytes = aesCtr.encrypt(textBytes)
        var encryptedHex = aesjs.utils.hex.fromBytes(encryptedBytes)
        return encryptedHex
    } else if (type == "decrypt") {
        var key = aesjs.utils.utf8.toBytes(hash.substring(0, 32))
        var counter = new aesjs.Counter(count)
        var aesCtrDecrypt = new aesjs.ModeOfOperation.ctr(key, counter)
        const decryptedBytes = aesCtrDecrypt.decrypt(aesjs.utils.hex.toBytes(data))
        const decryptedText = aesjs.utils.utf8.fromBytes(decryptedBytes)        
        return decryptedText
    } else {
        throw "function cryptoKey(), param 'type' not support"
    }
}

// 加密/解密选项
const descCryptoType = ["encrypt", "decrypt"]

function main() {
    LogReset(1)

    var count = _G("count")
    if (!count) {
        count = new Date().getTime()
        _G("count", count)
    }

    var walletAddress = null
    if (cryptoType == 1) {
        exchange.IO("key", cryptoKey(descCryptoType[cryptoType], keyData, password, count))
        walletAddress = exchange.IO("address")
        Log("载入秘钥，钱包地址：", walletAddress)
    } else {
        Log("加密后的秘钥：", cryptoKey(descCryptoType[cryptoType], keyData, password, count))
        return 
    }
    
    Log("钱包ETH余额：", toAmount(exchange.IO("api", "eth", "eth_getBalance", walletAddress, "latest"), 18))
    
    // sDAI/sUSDe 池合约地址和ABI
    var poolAddress = "0x167478921b907422F8E88B43C4Af2B8BEa278d3A"
    // 合约ABI
    var poolABI = `[{"name":"Transfer","inputs":[{"name":"sender","type":"address","indexed":true},{"name":"receiver","type":"address","indexed":true},{"name":"value","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"Approval","inputs":[{"name":"owner","type":"address","indexed":true},{"name":"spender","type":"address","indexed":true},{"name":"value","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"TokenExchange","inputs":[{"name":"buyer","type":"address","indexed":true},{"name":"sold_id","type":"int128","indexed":false},{"name":"tokens_sold","type":"uint256","indexed":false},{"name":"bought_id","type":"int128","indexed":false},{"name":"tokens_bought","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"TokenExchangeUnderlying","inputs":[{"name":"buyer","type":"address","indexed":true},{"name":"sold_id","type":"int128","indexed":false},{"name":"tokens_sold","type":"uint256","indexed":false},{"name":"bought_id","type":"int128","indexed":false},{"name":"tokens_bought","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"AddLiquidity","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"invariant","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidity","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidityOne","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_id","type":"int128","indexed":false},{"name":"token_amount","type":"uint256","indexed":false},{"name":"coin_amount","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RemoveLiquidityImbalance","inputs":[{"name":"provider","type":"address","indexed":true},{"name":"token_amounts","type":"uint256[]","indexed":false},{"name":"fees","type":"uint256[]","indexed":false},{"name":"invariant","type":"uint256","indexed":false},{"name":"token_supply","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"RampA","inputs":[{"name":"old_A","type":"uint256","indexed":false},{"name":"new_A","type":"uint256","indexed":false},{"name":"initial_time","type":"uint256","indexed":false},{"name":"future_time","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"StopRampA","inputs":[{"name":"A","type":"uint256","indexed":false},{"name":"t","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"ApplyNewFee","inputs":[{"name":"fee","type":"uint256","indexed":false},{"name":"offpeg_fee_multiplier","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"SetNewMATime","inputs":[{"name":"ma_exp_time","type":"uint256","indexed":false},{"name":"D_ma_time","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"stateMutability":"nonpayable","type":"constructor","inputs":[{"name":"_name","type":"string"},{"name":"_symbol","type":"string"},{"name":"_A","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_offpeg_fee_multiplier","type":"uint256"},{"name":"_ma_exp_time","type":"uint256"},{"name":"_coins","type":"address[]"},{"name":"_rate_multipliers","type":"uint256[]"},{"name":"_asset_types","type":"uint8[]"},{"name":"_method_ids","type":"bytes4[]"},{"name":"_oracles","type":"address[]"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"exchange","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange_received","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"exchange_received","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"_dx","type":"uint256"},{"name":"_min_dy","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"add_liquidity","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_min_mint_amount","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"add_liquidity","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_min_mint_amount","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"},{"name":"_min_received","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"},{"name":"_min_received","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_imbalance","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_max_burn_amount","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity_imbalance","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_max_burn_amount","type":"uint256"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"},{"name":"_receiver","type":"address"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"remove_liquidity","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"_min_amounts","type":"uint256[]"},{"name":"_receiver","type":"address"},{"name":"_claim_admin_fees","type":"bool"}],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"nonpayable","type":"function","name":"withdraw_admin_fees","inputs":[],"outputs":[]},{"stateMutability":"view","type":"function","name":"last_price","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ema_price","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_p","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"price_oracle","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"D_oracle","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"transfer","inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"transferFrom","inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"approve","inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"nonpayable","type":"function","name":"permit","inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_deadline","type":"uint256"},{"name":"_v","type":"uint8"},{"name":"_r","type":"bytes32"},{"name":"_s","type":"bytes32"}],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"view","type":"function","name":"DOMAIN_SEPARATOR","inputs":[],"outputs":[{"name":"","type":"bytes32"}]},{"stateMutability":"view","type":"function","name":"get_dx","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"dy","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_dy","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"},{"name":"dx","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"calc_withdraw_one_coin","inputs":[{"name":"_burn_amount","type":"uint256"},{"name":"i","type":"int128"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"totalSupply","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_virtual_price","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"calc_token_amount","inputs":[{"name":"_amounts","type":"uint256[]"},{"name":"_is_deposit","type":"bool"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"A_precise","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"balances","inputs":[{"name":"i","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"get_balances","inputs":[],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"view","type":"function","name":"stored_rates","inputs":[],"outputs":[{"name":"","type":"uint256[]"}]},{"stateMutability":"view","type":"function","name":"dynamic_fee","inputs":[{"name":"i","type":"int128"},{"name":"j","type":"int128"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"ramp_A","inputs":[{"name":"_future_A","type":"uint256"},{"name":"_future_time","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"stop_ramp_A","inputs":[],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_new_fee","inputs":[{"name":"_new_fee","type":"uint256"},{"name":"_new_offpeg_fee_multiplier","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_ma_exp_time","inputs":[{"name":"_ma_exp_time","type":"uint256"},{"name":"_D_ma_time","type":"uint256"}],"outputs":[]},{"stateMutability":"view","type":"function","name":"N_COINS","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"coins","inputs":[{"name":"arg0","type":"uint256"}],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"fee","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"offpeg_fee_multiplier","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"admin_fee","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"initial_A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"future_A","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"initial_A_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"future_A_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"admin_balances","inputs":[{"name":"arg0","type":"uint256"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ma_exp_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"D_ma_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"ma_last_time","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"name","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"symbol","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"decimals","inputs":[],"outputs":[{"name":"","type":"uint8"}]},{"stateMutability":"view","type":"function","name":"version","inputs":[],"outputs":[{"name":"","type":"string"}]},{"stateMutability":"view","type":"function","name":"balanceOf","inputs":[{"name":"arg0","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"allowance","inputs":[{"name":"arg0","type":"address"},{"name":"arg1","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"nonces","inputs":[{"name":"arg0","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"salt","inputs":[],"outputs":[{"name":"","type":"bytes32"}]}]`

    // 注册ABI
    exchange.IO("abi", poolAddress, poolABI)

    // 获取池子中的代币地址、名称
    var token0Address = exchange.IO("api", poolAddress, "coins", 0)
    var token1Address = exchange.IO("api", poolAddress, "coins", 1)    
    var token0Name = exchange.IO("api", token0Address, "symbol")
    var token1Name = exchange.IO("api", token1Address, "symbol")
    var token0Decimals = exchange.IO("api", token0Address, "decimals")
    var token1Decimals = exchange.IO("api", token1Address, "decimals")

    var sDAI = {}
    var sUSDe = {}
    if (token0Name == "sDAI") {
        sDAI["name"] = token0Name
        sDAI["address"] = token0Address
        sDAI["idx"] = 0
        sDAI["decimals"] = token0Decimals ? token0Decimals : 18
    } else {
        throw "pool error"
    }
    if (token1Name == "sUSDe") {
        sUSDe["name"] = token1Name
        sUSDe["address"] = token1Address
        sUSDe["idx"] = 1
        sUSDe["decimals"] = token1Decimals ? token1Decimals : 18
    } else {
        throw "pool error"
    }

    // 假设 DAI 入手成本价： 0.9929
    var entryPriceForDAI = 0.9929
    
    while (true) {
        var sDAI_Balance = exchange.IO("api", sDAI["address"], "balanceOf", walletAddress)
        var sUSDe_Balance = exchange.IO("api", sUSDe["address"], "balanceOf", walletAddress)
        if (!sDAI_Balance || !sUSDe_Balance) {
            Sleep(1000 * 5)
            continue 
        }
        
        var tbl = {"type": "table", "title": "data", "cols": ["tokenName", "address", "idx", "decimals", "balance"], "rows": []}
        tbl["rows"].push([sDAI["name"], sDAI["address"], sDAI["idx"], sDAI["decimals"], toAmount(sDAI_Balance, sDAI["decimals"])])
        tbl["rows"].push([sUSDe["name"], sUSDe["address"], sUSDe["idx"], sUSDe["decimals"], toAmount(sUSDe_Balance, sUSDe["decimals"])])

        // 监控兑换价格，根据 DAI 入手成本价，计算实时利润等信息
        var amountIn = 100000
        var ret = getBuyProfit(poolAddress, sDAI, sUSDe, amountIn, entryPriceForDAI)
        if (!ret) {
            Sleep(1000 * 5)
            continue 
        }

        var profit = ret["profit"] 
        var amountOut = ret["amountOut"]
        var sDAI_sUSDe_price = ret["sDAI_sUSDe_price"]
        if (profit > 1000 && sDAI_Balance > amountIn) {
            Log("达到兑换条件，开始执行 sDAI -> sUSDe 兑换交易...")

            /* 兑换操作代码仅为教学演示，该功能请慎用，请先测试 
            executeTrade(poolAddress, sDAI, sUSDe, amountIn, 0.999*amountOut)
            */
        }

        LogStatus(_D(), ", amountIn:", amountIn, ", amountOut:", amountOut, ", sDAI_sUSDe_price:", sDAI_sUSDe_price, ", profit:", profit, "\n`" + JSON.stringify(tbl) + "`")
        Sleep(1000 * 60)
    }
}

END

মূল কৌশলের নকশা ধারণা অনুসারে, লক্ষ্য হওয়া উচিত চিত্রে দেখানো চরম বাজার পরিস্থিতির মতো পরিস্থিতি ক্যাপচার করা।

আপনার পড়া এবং সমর্থনের জন্য ধন্যবাদ।