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?
The only line of input contains an integer m (1 ≤ m ≤ 100 000) — the required number of trailing zeroes in factorial.
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.
1
5
5 6 7 8 9
5
0
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:给一个数m表示一个数的阶乘的值后边0的个数,问这样的数有几个并写出来
题解:判断5的个数详解见http://www.cnblogs.com/tonghao/p/4823114.html
因为用二分时区间开的太小没发现 错了几个小时
#include<stdio.h>
#include<string.h>
#include<string>
#include<math.h>
#include<algorithm>
#define LL long long
#define PI atan(1.0)*4
#define DD double
#define MAX 100100
#define mod 100
#define dian 1.000000011
#define INF 0x3f3f3f
using namespace std;
int fun(int x)
{
int cnt=0;
while(x)
{
cnt+=x/5;
x/=5;
}
return cnt;
}
int fen(int m)
{
int left=0;
int right=1001000000;
int mid,ans;
ans=0;
while(left<=right)
{
mid=(left+right)/2;
if(fun(mid)>=m)
{
right=mid-1;
//ans=mid;
}
else
left=mid+1;
}
return left;
}
int s[MAX];
int main()
{
int n,m,j,i,t,k;
while(scanf("%d",&n)!=EOF)
{
int sum=0;k=0;
int L,R;
L=fen(n);R=fen(n+1);
// if(L==0||fun(R-1)!=n)
// {
// printf("0
");
// continue;
// }
for(i=L;i<R;i++)
{
if(fun(i)==n)
{
sum++;
s[k++]=i;
}
}
printf("%d
",sum);
if(sum!=0)
{
for(i=0;i<k-1;i++)
printf("%d ",s[i]);
printf("%d
",s[k-1]);
}
}
return 0;
}