大数的加法运算，杭电oj-1002

原题地址：http://acm.hdu.edu.cn/showproblem.php?pid=1002

 

【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

【AC代码】

 #include<stdio.h>
 #include<string.h>
 #define max(a, b) a > b ? a:b

 char a[];
 char b[];
 char c[];
 int i;

 void reverse(char *a)
 {
     int aa = strlen(a);
     char t;
     for(i=; i<aa/; i++)
     {
         t = a[i];
         a[i] = a[aa--i];
         a[aa--i] = t;
     }
 }
 void add(char *a, char *b, char *c)
 {
         int cc = , aa = strlen(a), bb = strlen(b);
         int len = max(aa, bb);
            for(i=; i<aa; i++)
            {
             a[i] = a[i]-'';
         }
            for(i=; i<bb; i++)
         {
               b[i] = b[i]-'';
         }
         for(i=; i<len; i++)
         {
             c[i] = (a[i]+b[i]+cc) %  + '';
             cc = (a[i]+b[i]+cc) / ;
         }
            if(cc) c[i++] = cc + '';
           c[i] = '\0';
 }
 void print(char *c)
 {
     for(i = strlen(c)-; i>=; i--)
         printf("%c", c[i]);
         printf("\n");
 }
 main()
 {
     int n, j;
     scanf("%d", &n);
     for(j=; j<=n; j++)
     {
         memset(a, , sizeof(a));
         memset(b, , sizeof(b));
         memset(c, , sizeof(c));
         scanf("%s %s", a, b);
         printf("Case %d:\n", j);
         printf("%s + %s = ", a, b);
         reverse(a), reverse(b);
         add(a, b, c);
         print(c);
           if(j != n) printf("\n");
     }
 }