Product 

 

The Problem

The problem is to multiply two integers X, Y. (0<=X,Y<10²⁵⁰)

The Input

The input will consist of a set of pairs of lines. Each line in pair contains one multiplyer.

The Output

For each input pair of lines the output line should consist one integer the product.

Sample Input

 

12122222222222222222222222222

 

Sample Output

 

144444444444444444444444444

1 #include
     
       2 #include
      
        3  4 #define maxn 2005 5  6 int main() 7 { 8     char a[maxn],b[maxn]; 9     int ans[maxn];10     int i,j,k;11     int la,lb;12     while(scanf("%s%s",a,b) != EOF)13     {14         la=strlen(a);15         lb=strlen(b);16         memset(ans,0,sizeof(ans));17         for(i=la-1;i>=0;i--)18         {19             for(j=lb-1,k=la-1-i;j>=0;j--)//大数相乘模拟手算，关键在于错位，即k=la-1-i20             {21                 ans[k++] += (a[i]-'0')*(b[j]-'0');//ans[0]存的是个位，ans[1]存的是十位，ans[2]存的是百位……22             }23         }24         for(i=0;i
       
        9)//进位27             {28                 ans[i+1]+=ans[i]/10;//因为是乘法，不再像加法一样是进1还是不进位了29                 ans[i]%=10;//只留一位30             }31         }32         for(i=maxn-1;i>=0;i--)33         {34             if(ans[i])//忽略前导035                 break;36         }37         if(i>=0)38         {39             for(;i>=0;i--)40             {41                 printf("%d",ans[i]);42             }43         }44         else45             printf("0");46         printf("\n");47     }48     return 0;49 }