HDU 1042大数运算

 1 #include<stdio.h>
 2 #include<string.h>
 3 #define maxn 40005//10000阶乘后的位数大约为40000一开始开得太大结果超时了，最后数组开销了之后便AC
 4 
 5 int main()
 6 {
 7     int i, j, c, s, n, f[maxn];
 8        
 9     while(scanf("%d",&n)!= EOF)
10     {    
11       memset(f,0,sizeof(f));
12       f[0] = 1; 
13       for(i=2; i<=n; i++)
14       {
15          c = 0; 
16         for(j=0; j<maxn; j++)
17         {
18           s = f[j]*i + c;
19           f[j] = s%10;
20           c = s/10;
21         }
22       }
23       for(j=maxn-1; j>=0; j--)
24         if(f[j]) break;
25       for(i=j; i>=0; i--)
26         printf("%d",f[i]);
27       printf("\n");
28     }
29     return 0;
30 }                    
31