SZU:B47 Big Integer II

Judge Info

• Memory Limit: 32768KB
• Case Time Limit: 10000MS
• Time Limit: 10000MS
• Judger: Normal

Description

Please calculate the answer of A*B, both A and B are integer.

Input

The first line of input contains , the number of test cases. There is only line for each test case. It contains two integers .

Output

For each test case, output A*B in one line.

Sample Input

3
1 2
1 1
-1 -1

Sample Output

2
1
1

Ps : 算法课的小练习，通过字符串处理。注意0就OK了。

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

 char A[];
 char B[];
 int C[++];

 char *revstr(char *str, int len){
     char *start = str;
     char *end = str + len - ;
     char ch;
     if(str != ){
         while(start < end){
             ch = *start;
             *start ++ = *end;
             *end-- = ch;
         }
     }
     return str;
 }

 int main(int argc, char const *argv[])
 {
     int t, i, j, lenA, lenB, len, Amark, Bmark, mark;
     scanf("%d", &t);
     while(t--){

         mark=;
         Amark = ;
         Bmark = ;

         memset(A, '', sizeof(A));
         memset(B, '', sizeof(B));
         memset(C, , sizeof(C));
         scanf("%s", A);
         scanf("%s", B);
         lenA = strlen(A);
         lenB = strlen(B);

         if(A[] == '-'){
             for(i=;i<lenA;++i)
                 A[i-] = A[i];
             A[i-]= '\0';
             A[i] = '';
             Amark = ;
             lenA--;
         }

         if(B[] == '-'){
             for(i=;i<lenB;++i)
                 B[i-] = B[i];
             B[i-] = '\0';
             B[i] = '';
             Bmark = ;
             lenB--;
         }
         revstr(A,lenA);
         revstr(B,lenB);
         A[lenA] = '\0';
         B[lenB] = '\0';

         for(i=;i<lenB;++i){
             for(j=;j<lenA;++j){
                 C[j+i]+=(B[i]-'')*(A[j]-'');
             }
         }
         len = lenA + lenB;
         for(i=;i<len;++i){
             if(C[i] > ){
                 C[i+]+=C[i]/;
                 C[i] %= ;
             }
         }
          while(!C[len-]){
                  len--;
          }
          //printf("len = %d\n", len);
          if(len == ){ printf("0\n"); continue;}
          if(len > - && Amark != Bmark)
              putchar('-');
         for(i=len-;i>=;i--)
             printf("%d", C[i]);

         printf("\n");
     }

     return ;
 }