hdu1024 N! （数组模拟乘法过程）

N!

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 65655    Accepted Submission(s): 18807

Problem Description

Given an integer N(0 ≤ N ≤ 10000), your task is to calculate N!

Input

One N in one line, process to the end of file.

Output

For each N, output N! in one line.

Sample Input

1
2
3

Sample Output

1
2
6

Author

JGShining（极光炫影）

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第一次 想这数组开小点1w把。。其实真不小了。。

可我还是太嫩了。。原来要开到35700。。

#include <stdio.h>
#include <string.h>
using namespace std;
#define N 35700
int main()
{
  int n;
  char num[N];
  while(scanf("%d",&n)!=EOF)
  {
    memset(num,'0',sizeof(num));
    num[0]='1';
    for(int i=2;i<=n;i++)
    {
      int r=0,k;
      for(int j=0;j<N;j++)
      {
        k=(num[j]-'0')*i+r;
        num[j]=k%10+'0';
        r=k/10;
      }
    }
    int i;
    for(i=N-1;i>=0;i--)
    if(num[i]!='0')
    break;
    for(int j=i;j>=0;j--)
    printf("%c",num[j]);
    printf("\n");
  }
  return 0;
}