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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题目描写叙述
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.
例子输入
12 5 30
例子输出
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; }