HDU 1492 The number of divisors(约数) about Humble Numbers 数论

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define INF     0x3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;

int main()
{
    //FIN

    LL n;
    while(~scanf("%lld",&n)&&n)
    {
        LL res=1;
        int a=1,b=1,c=1,d=1;
        while(n!=1&&n%2==0)  {a++;n/=2;}
        while(n!=1&&n%3==0)  {b++;n/=3;}
        while(n!=1&&n%5==0)  {c++;n/=5;}
        while(n!=1&&n%7==0)  {d++;n/=7;}
        res=a*b*c*d;
        printf("%lld\n",res);
    }

}