因子个数

题目：https://www.nowcoder.com/pat/2/problem/264

#include<iostream>
#include<algorithm>
#include<string.h>
#include<stdio.h>
using namespace std;
int prime[100005];
//素数表
void prime_table()
{
    int i, j;
    for (i = 2; i<100005; i++)
    if (prime[i] == 0)
    for (j = 2 * i; j<100005; j += i)
        prime[j] = 1;
}

int main()
{
    int n, t = 0;
    int a[20000];
    prime_table();
    for (int i = 2; i<100005; i++)
    if (prime[i] == 0)
    {
        a[t] = i;
        t++;
    }
    while (~scanf("%d", &n))
    {
        int cnt = 0, i = 0;
        while (n != 1)
        {
            if (n%a[i] != 0)
                i++;
            else if (n%a[i] == 0)
            {
                while (n%a[i] == 0)
                    n /= a[i];
                cnt++;
            }
        }
        printf("%d
", cnt);
    }
    return 0;
}