分解質因子

任何一個合數可以分解爲幾個質數的乘積，這些質數也必然是這個合數的約數。 

#include<bits/stdc++.h>
using namespace std;
vector<int> fun(int n) {
	vector<int> v;
	for (int i = 2; i <= n; i++) {
		while (n%i == 0) {
			n /= i;
			v.push_back(i);
		}
	}
	return v;
}
int main() {
	int n;
	cin >> n;
	vector<int> v = fun(n);
	for (auto it = v.begin(); it != v.end(); it++) {
		cout << *it << " ";
	}
}