A + B Problem II Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 264743 Accepted Submission(s): 51237

Problem Description I have a very simple problem for you. Given two integers A and B, your job is to calculate the Sum of A + B.

Input The first line of the input contains an integer T(1<=T<=20) which means the number of test cases. Then T lines follow, each line consists of two positive integers, A and B. Notice that the integers are very large, that means you should not process them by using 32-bit integer. You may assume the length of each integer will not exceed 1000.

Output For each test case, you should output two lines. The first line is "Case #:", # means the number of the test case. The second line is the an equation "A + B = Sum", Sum means the result of A + B. Note there are some spaces int the equation. Output a blank line between two test cases.

Sample Input

2 1 2 112233445566778899 998877665544332211

Sample Output

Case 1: 1 + 2 = 3

Case 2: 112233445566778899 + 998877665544332211 = 1111111111111111110

简单大数:模拟手算。

为了便于计算,要将两个整数读成字符串,并且倒置(也有防止加法溢出额情况)

ac代码

#include <stdio.h>
#include <cstring>

#define maxn 1000

char a[maxn]; char b[maxn]; char c[maxn+3];

void change(char a[]){ int len=strlen(a); for(int i=0;i==0||i<len/2;i++){ int temp; temp=a[i]-'0'; a[i]=a[len-i-1]-'0'; a[len-i-1]=temp; } if((len%2)==1) a[len/2]=a[len/2]-'0'; }

void tsum(char a[],char b[],char c[]){ int yu=0; int temp=0; for(int i=0;i<maxn;i++){ temp=a[i]+b[i]+yu; c[i]=temp%10; yu=temp/10; } }

int main(){ int n; while(scanf("%d",&n)!=EOF){ int ca=1; int first=0; while(n--){ memset(a,0,sizeof(a)); memset(b,0,sizeof(b)); if(first){ printf("\n"); }else{ first=1; } printf("Case %d:\n",ca++); scanf("%s%s",a,b); printf("%s + %s = ",a,b); change(a); change(b); tsum(a,b,c); int start=0; for(start=maxn-1;c[start]==0;start--); for(;start>=0;start--) printf("%d",c[start]); printf("\n"); } } return 0; }