高精度加法算法

#include <iostream>

using namespace std;

using MyInt = __int128_t; // 又一种无赖的解法

int t;
string s1, s2, s3;

MyInt conv(const string& s) {

  MyInt ans = 0;
  bool negative = false;
  for (const auto& c : s) {
    if (c == '-') { negative = true; continue; }
    ans = ans * 10 + c - '0';
  }

  return negative ? -ans : ans;
}

int main(void) {
  cin >> t;
  for (int i = 1; i <= t; ++i) {
    cin >> s1 >> s2 >> s3;
    auto a = conv(s1), b = conv(s2), c = conv(s3);
    printf("Case #%d: %s\n", i, a + b > c ? "true" : "false");
  }
}