Trailing Zeroes (III) 假设n!后面有x个0.现在要求的是，给定x，要求最小的n； 判断一个n!后面有多少个0，通过n/5+n/25+n/125+...

/**
题目：Trailing Zeroes (III)
链接：https://vjudge.net/contest/154246#problem/N
题意：假设n!后面有x个0.现在要求的是，给定x，要求最小的n；
思路：判断一个n!后面有多少个0，通过n/5+n/25+n/125+...
*/#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<cmath>
using namespace std;
typedef long long ll;
const int maxn = *1e8+;
int num(int m)
{
int cnt = ;
while(m>){
cnt += m/;
m /= ;
}
return cnt;
}
int main()
{
int T, cas=, q;
cin>>T;
while(T--)
{
scanf("%d",&q);
int lo = , hi = maxn;
int m;
int mis = maxn;
while(lo<=hi){
m = (lo+hi)/;
int t = num(m);
if(t>=q){
if(t==q) mis = min(mis,m);
hi = m-;
}else
{
lo = m+;
}
}
if(mis==maxn)
printf("Case %d: impossible\n",cas++);
else
printf("Case %d: %d\n",cas++,mis); }
return ;
}