因子个数

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

 1 #include<iostream>
 2 #include<algorithm>
 3 #include<string.h>
 4 #include<stdio.h>
 5 using namespace std;
 6 int prime[100005];
 7 //素数表
 8 void prime_table()
 9 {
10     int i, j;
11     for (i = 2; i<100005; i++)
12     if (prime[i] == 0)
13     for (j = 2 * i; j<100005; j += i)
14         prime[j] = 1;
15 }
16 
17 int main()
18 {
19     int n, t = 0;
20     int a[20000];
21     prime_table();
22     for (int i = 2; i<100005; i++)
23     if (prime[i] == 0)
24     {
25         a[t] = i;
26         t++;
27     }
28     while (~scanf("%d", &n))
29     {
30         int cnt = 0, i = 0;
31         while (n != 1)
32         {
33             if (n%a[i] != 0)
34                 i++;
35             else if (n%a[i] == 0)
36             {
37                 while (n%a[i] == 0)
38                     n /= a[i];
39                 cnt++;
40             }
41         }
42         printf("%d\n", cnt);
43     }
44     return 0;
45 }

 

posted @ 2018-01-16 22:28  ouyang_wsgwz  阅读(141)  评论(0)  编辑  收藏  举报