2019ccpc Qinhuangdao / Gym102361 D - Decimal sign

Meaning of the questions:

Given n, determines whether or not 1 / n infinite loop in decimal

Solution:
determining whether the n-factor can comprise other than 2,5

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<stack>
#include<algorithm>
#include<map>
#include<queue>
#include<vector>
using namespace std;
#define INF 0x3f3f3f3f
#define MAXN 100000+50
#define MAXM 30000
#define ll long long
#define per(i,n,m) for(int i=n;i>=m;--i)
#define rep(i,n,m) for(int i=n;i<=m;++i)
#define mod 1000000000 + 7
#define mian main
#define mem(a, b) memset(a, b, sizeof a)
#ifndef ONLINE_JUDGE
#define dbg(x) cout << #x << "=" << x << endl;
#else
#define dbg(x)
#endif
inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = 10 * x + ch - '0';
        ch = getchar();
    }
    return x * f;
}
inline ll readll()
{
    ll x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = 10 * x + ch - '0';
        ch = getchar();
    }
    return x * f;
}
int main ()
{
    int t;
    scanf("%d",&t);
    while(t--){
        int n;
        scanf("%d",&n);
        while(n%5==0)n/=5;
        while(n%2==0)n/=2;
        if(n==1)printf("No\n");
        else printf("Yes\n");
    }
}