Choose a nickname

1. 题目

1.1 智能合约CaptureTheEther会记录每个玩家的昵称。要完成此挑战，请将您的昵称设置为非空字符串。智能合约在地址的 Ropsten 测试网络上运行0x71c46Ed333C35e4E6c62D32dc7C8F00D125b4fee。
1.2 题目代码

// SPDX-License-Identifier: MIT
pragma solidity ^0.4.21;

// Relevant part of the CaptureTheEther contract.
contract CaptureTheEther {
    mapping (address => bytes32) public nicknameOf;

    function setNickname(bytes32 nickname) public {
        nicknameOf[msg.sender] = nickname;
    }
}

// Challenge contract. You don't need to do anything with this; it just verifies
// that you set a nickname for yourself.
contract NicknameChallenge {
    CaptureTheEther cte = CaptureTheEther(msg.sender);
    address player;

    // Your address gets passed in as a constructor parameter.
    function NicknameChallenge(address _player) public {
        player = _player;
    }

    // Check that the first character is not null.
    function isComplete() public view returns (bool) {
        return cte.nicknameOf(player)[0] != 0;
    }
}

2. 分析

2.1 只需要将成功调用setNickname() 函数即可
2.2 考点在于如何将字符串转为64位 16进制的数据类型
我在idea 编写了一个程序来解决这个问题

package daily_temp;

/**
 * @Auther: 柚子
 * @Date:2023/3/24年03月24日 15:43
 * @Description:daily_temp
 * @version: 1.0
 */
public class convertStringToHex {
    public static void main(String[] args) {
        covertStringToHex("biyou");
    }
    
    static void covertStringToHex(String str) {
        StringBuffer sb = new StringBuffer();

        char[] chars = str.toCharArray();

        for(char c : chars) {
            String charToHex = Integer.toHexString(c);
            sb.append(charToHex);
        }

        int length = sb.length();
        for (int i = 0; i < 64 - length; i++) {
            sb.append(0);
        }

        System.out.println("0x" + sb.toString());
    }

}

输入为 biyou 运行结果为：
![image-20240412144152362](Choose a nickname/image-20240412144152362.png)
以 0x6269796f75000000000000000000000000000000000000000000000000000000 为参数，调用 setNickname() 函数即可

3. 解题

3.1 部署
3.2 将转化好的数据以参数的形式传入
3.3
![image-20240412144208239](Choose a nickname/image-20240412144208239.png)