南阳oj 400 I'll play a trick on you （细节规律题 简单的字符串处理）

I'll play a trick on you

时间限制：3000 ms  |  内存限制：65535 KB

难度：1

描述

Please look the picture carefully. Then I'll give you two integers and your task is output the third one.
Please never doubt the picture.

输入

The first line is a number T(1<=T<=30), represents the number of case. The next T blocks follow each indicates a case.
Each case contains two integers A,B (1<=B<=A<=10^100)

输出

For each case, output the number of case and the third integer.

样例输入

399 7245 2739 18

样例输出

271821

来源

2011 Alibaba Programming Contest

难点：

这道题很容易误认为就是直接的加减 但是注意到后面的7

思路：

实际上是 各个数位的数相加的和 加起来就是后来的数 

代码如下：

#include<stdio.h>#include<string.h> int main(){int n,i,s1,s2;char s[110],m[110];scanf("%d",&n);while(n--){s1=s2=0;scanf("%s%s",s,m);for(i=0;i<strlen(s);i++)s1+=(s[i]-'0');for(i=0;i<strlen(m);i++)s2+=(m[i]-'0');printf("%d\n",s1+s2);}return 0;}}