hdu 1042 N!

N!

Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 66786 Accepted Submission(s): 19147

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

Sample Output

Author

JGShining（极光炫影）

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基础的大数问题，注意进位，将数字全部压入数组保存。

题意：求n！，必须大数。

附上代码：

 1 #include <cstdio>
 2 #include <iostream>
 3 using namespace std;
 4 int main()
 5 {
 6     int i,j,n,k,s,m,t;
 7     int a[100005];      //保存n!
 8     while(~scanf("%d",&n))
 9     {
10         a[0]=1;
11         s=1;    //记录数组的位数
12         for(i=1; i<=n; i++)
13         {
14             k=0;       //记录进位的值
15             for(j=0; j<s; j++)  //每一位都要乘以i
16             {
17                 t=a[j]*i+k;
18                 a[j]=t%10;    //只保留个位数
19                 k=t/10;      //去掉最后一位
20             }
21             while(k)        //将k的值全部压入数组
22             {
23                 a[s++]=k%10;
24                 k/=10;
25             }
26         }
27         for(i=s-1; i>=0; i--) //注意倒着输出
28             printf("%d",a[i]);
29         printf("
");
30     }
31     return 0;
32 }