大数加法2——在较短的加数前补充前导零

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>

int main()
{
    char str1[255], str2[255];
    int num1[255] = { 0 }, num2[255] = { 0 };//用于存放加数，且较短者补前导零
    int sum[255] = { 0 };
    int length1, length2, length;
    int i, j;

    gets(str1);
    gets(str2);
    length1 = strlen(str1);
    length2 = strlen(str2);
    length = length1 > length2 ? length1 : length2;

    //将两个加数存入到num[]中
    for (i = length - 1,j = length1 - 1; j >= 0; i--,j--)
    {
        num1[i] = str1[j] - ‘0‘;
    }

    for (i = length - 1, j = length2 - 1; j >= 0; i--, j--)
    {
        num2[i] = str2[j] - ‘0‘;
    }

    //从后往前进行加法计算
    for (i = length - 1; i >= 0; i--)
    {
        sum[i] = sum[i] + num1[i] + num2[i];
        if ((sum[i] >= 10) && (i != 0))
        {
            sum[i] = sum[i] - 10;
            sum[i - 1]++;//表示进位
        }
    }

    for (i = 0; i < length; i++)
    {
        printf("%d", sum[i]);
    }

    return 0;
}