题解 | #Integer Inquiry#

#include "stdio.h"
#include "string"
#include "algorithm"
using namespace std;
char buf[110][110];
int n = 0;//记录输入的行数为（n-1）

string addString(string num1,string num2){//字符串相加
    int length = num1.size()>num2.size()?num1.size():num2.size();
    while (num1.size() < length)
        num1 = "0" + num1;//补齐高位
    while (num2.size() < length)
        num2 = "0" + num2;//同理，补齐高位
    string num3 = "";int carry = 0;
    int temp;
    for (int i = length-1; i >= 0; --i) {
        temp = num1[i]-'0' + num2[i]-'0'+carry;
        if (temp > 9){
            num3 += temp-10+'0';
            carry = 1;
        } else{
            num3 += temp+'0';
            carry = 0;
        }
    }
    if (carry == 1)
        num3 += '1';
    reverse(num3.begin(),num3.end());
    return num3;
}

void Init(string &num1){//字符串初始化，消去前导0
    int i = 0;
    while (num1[i] == '0')
        ++i;
    num1.erase(0,i);
}

int main(){
    while (scanf("%s",buf[n++])!=EOF){
        string num = buf[n-1];
        if (num == "0")
            break;
    }
    n = n-1;
    string sum = "";
    for (int i = 0; i < n; ++i) {
        string num = buf[i];
        Init(num);
        sum = addString(sum,num);
    }
    printf("%s",sum.c_str());
}