N!
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.
Sample Input
1
2
3
Sample Output
1
2
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.
Sample Input
1
2
3
Sample Output
1
2
6
//由于大数求阶乘利用数组模拟乘法运算,所以必须从低位开始相乘 #include <stdio.h> #include <string.h> int a[50000]; int main() { int n; while(~scanf("%d",&n)) { memset(a,sizeof(a)); a[0]=1; int p=1; //p为阶乘所到位数的下一个所以输出时不需要判断0 for(int i=2;i<=n;i++) { int c=0,j; //c为相乘溢出的值 for(j=0;j<p;j++) { int s=a[j]*i+c; a[j]=s%10; c=s/10; } while(c) { a[j++]=c%10; c/=10; } p=j; } for(int j=p-1;j>=0;j--) printf("%d",a[j]); printf("\n"); } return 0; }