写在前面 这道题不难，我用这道题学习了一下字符串拼接和字符串加法进位，其实还想学习一下atoi函数和stoi函数，后来也没用。我这道题有很多细节在一开始并没有注意，导致出现了很多问题，想把代码分享出来，希望之后的同学注意细节。

#include <math.h>
#include <string.h>

#include <iostream>

int main() {
  int T = 0;
  std::cin >> T;
  for (int i = 0; i < T; i++) {
    int jinWei = 0;  // 这里只可能是0或1其他的情况都是错的

    std::string count1;
    std::string count2;
    std::string result;
    std::cin >> count1 >> count2;

    std::string result1 = count1;//16 17两行是用来保存输入的字符串不被前导零覆盖，输出使用
    std::string result2 = count2;
    int length1 = std::max(count1.length(), count2.length());

    // 22 到 32 部分是用来比较两字符串长度并且变为等长
    int lenMin = count1.length();
    int lenMax = count2.length();
    std::string m = "";
    for (int j = 0; j < std::abs(lenMax - lenMin); j++) {
      m = m + "0";
    }
    if (count1.length() > count2.length()) {
      count2 = m + count2;
    } else if (count1.length() < count2.length()) {
      count1 = m + count1;
    }

    for (int j = length1 - 1; j >= 0; j--) {
      int tempstr;
      int temp1 = 0;
      int temp2 = 0;
      temp1 = count1[j] - '0';
      temp2 = count2[j] - '0';
      int sum = temp1 + temp2 + jinWei;
      if (sum >= 10) {
        jinWei = 1;
      } else {
        jinWei = 0;
      }
      int yuShu = (sum) % 10;
      tempstr = yuShu;
      result = std::to_string(tempstr) + result;
    }

    std::cout << "Case " << i + 1 << ":" << std::endl;
    std::cout << result1 << " + " << result2 << " = ";
    if (jinWei == 1) {
      std::cout << "1";
    }
    std::cout << result << std::endl;
  }
}