C++ 式普通写法

#include<iostream>

using namespace std;

int a,b;

int main(){
  cin >> a >> b;
  cout << a + b;
  return 0;
}

高精度

#include<iostream>

using namespace std;

const int MAXN = 1e5 + 10;

long long r;
int c;
char op;

struct bigint{
  long long len,sz[MAXN] = {0};

  long long &operator [] (long long a){
    return sz[a];
  }

  void input(){
    string s;
    cin >> s;
    len = s.size();
    for (int i = 0; i < len; i++){
      sz[i] = s[len - i - 1] - '0';
    }
  }

  void output(){
    for (; len - 1 > 0 && !sz[len - 1]; len--){
    }

    for (int i = len - 1; i >= 0; i--){
      cout << sz[i];
    }
    cout << '\n';
  }
  bigint operator + (const bigint &b){
    bigint c;
    c.len = max(len,b.len) + 1;
    for (int i = 0; i < c.len; i++){
      c[i] = sz[i] + b.sz[i];
    }

    for (int i = 0; i < c.len - 1; i++){
      c[i + 1] += c[i] / 10,c[i] %= 10;
    }
    return c;
  }
}a,b,ans;

int main(){
  a.input(),b.input();
  ans = a + b;
  ans.output();
  return 0;
}