ZOJ 1115 Digital Roots

典型大数加法题

#include <stdio.h>#include <string>#include <iostream>#include <string.h>using namespace std;int main(){    string num;    while (cin >> num, num[0] != '0')    {        while (num.length() > 1)        {            string sum = "0";            for (int i = 0; i < num.length(); i++)            {                int temp = num[i] - '0';                int index = 0;                while (temp > 0)                {                    if (index == sum.length())                    {                        sum += "0";                    }                    int s = (sum[index] - '0') + temp;                    sum[index++] = '0' + s % 10;                    temp = s / 10;                }            }            num = sum;        }        printf("%s\n", num.c_str());    }    return  0;}