课堂原代码,码风规范,简洁易懂

#include<iostream>
using namespace std;
string s, t;
int a[10001], b[10001], c[10002];
int main(){
    cin >> s >> t;
    if(s.size() < t.size()){//a<b
        cout << "-";
        swap(s, t);
    }else if(s.size() == t.size() && s < t){//a<b
        cout << "-";
        swap(s, t);
    }
    int lens = s.size();
    int lent = t.size();
    for(int i = 0; i < lens; i++){
        a[i] = s[lens - i - 1] - '0';
    }
    for(int i = 0; i < lent; i++){
        b[i] = t[lent - i - 1] - '0';
    }
    int len = max(lens, lent);
    for(int i = 0; i < len; i++){
        c[i] += (a[i] - b[i]);
        if(c[i] < 0){
            c[i] += 10;
            c[i + 1]--;
        }
    }
    bool flag = true;
    while(len > 1 && c[len - 1] == 0){
        len--;
    }
    for(int i = len - 1; i >= 0; i--){
        cout << c[i];
    }
    return 0;
}