2014辽宁ACM省赛 Prime Factors

问题 L: Prime Factors

时间限制: 1 Sec 内存限制: 128 MB

提交: 36 解决: 28

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题目描述
I'll give you a number , please tell me how many different prime factors in this number.
输入
There is multiple test cases , in each test case there is only one line contains a number N(2<=N<=100000). Process to the end of file.
输出
For each test case , output one line contains one number , indicating different prime factor in the number N.
样例输入
12 5 30
样例输出
2 1 3
提示
12 = 2 * 2 * 3

5 = 5

30 = 2 * 3 * 5

水题一道，打表，枚举质因子就完了。

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<vector>
using namespace std;
const int MAX=100000;
vector<int> f;
void init()
{
int k=0;
for(int i=2;i<=MAX;i++)
{
bool flag=true;
for(int j=2;j<=sqrt(i);j++)
{
if(i%j==0)
{
flag=false;
break;
}
}
if(flag)
f.push_back(i);
}
}
int main()
{
init();
int n;
while(cin>>n)
{
int cnt=0;
for(int i=0;i<f.size();i++)
{
if(n%f[i]==0)
{
cnt++;
n/=f[i];
while(n%f[i]==0)
{
n/=f[i];
}
}
}
cout<<cnt<<endl;
}
return 0;
}