codeforces 633B B. A Trivial Problem(数论)

B. A Trivial Problem
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Mr. Santa asks all the great programmers of the world to solve a trivial problem. He gives them an integer m and asks for the number of positive integers n, such that the factorial of n ends with exactly m zeroes. Are you among those great programmers who can solve this problem?

Input

The only line of input contains an integer m (1 ≤ m ≤ 100 000) — the required number of trailing zeroes in factorial.

Output

First print k — the number of values of n such that the factorial of n ends with m zeroes. Then print these k integers in increasing order.

Examples
input
1
output
5
5 6 7 8 9
input
5
output
0
Note

The factorial of n is equal to the product of all integers from 1 to n inclusive, that is n! = 1·2·3·...·n.

In the first sample, 5! = 120, 6! = 720, 7! = 5040, 8! = 40320 and 9! = 362880.

 题意:给一个m,问哪些数的阶乘的末尾0的个数为m;

思路:末尾0的个数为这些数中有多少个5,2的个数一定大于5,所以只需找5的个数就行;

AC代码:

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int m;
    scanf("%d",&m);
    int num,x,sum=0;
   for(int i=1;i<=100000;i++)
   {
       num=1;
       x=i;
       while(1)
       {
           if(x%5==0)
           {
               num++;
               x=x/5;
           }
           else break;
       }
       sum+=num;
       if(sum==m)
       {
           cout<<"5"<<"\n";
           for(int j=5*i;j<5*i+5;j++)
           {
               printf("%d ",j);
           }
           return 0;
       }
       else if(sum>m)
       {
           break;
       }
   }
   cout<<"0";
    return 0;
}
posted @ 2016-02-27 17:01  LittlePointer  阅读(441)  评论(0编辑  收藏  举报