swap三明治合约代码

以下是 swap 三明治合约代码的示例：

// SPDX-License-Identifier: MIT

pragma solidity ^.8.;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract SandwichSwap is Ownable {
    using SafeERC20 for IERC20;

    IERC20 public tokenA;
    IERC20 public tokenB;

    constructor(IERC20 _tokenA, IERC20 _tokenB) {
        tokenA = _tokenA;
        tokenB = _tokenB;
    }

    function swap(uint256 amountA, uint256 amountB) external {
        tokenA.safeTransferFrom(msg.sender, address(this), amountA);
        tokenB.safeTransfer(msg.sender, amountB);
    }

    function setTokenA(IERC20 _tokenA) external onlyOwner {
        tokenA = _tokenA;
    }

    function setTokenB(IERC20 _tokenB) external onlyOwner {
        tokenB = _tokenB;
    }
}

希望能够帮到你！