#include <iostream>
#include <vector>
using namespace std;
void primeFactors(int n) {
vector<int> factors;
while (n % 2 == 0) {
factors.push_back(2);
n = n / 2;
}
for (int i = 3; i*i <= n; i = i + 2) {
while (n % i == 0) {
factors.push_back(i);
n = n / i;
}
}
if (n > 2) {
factors.push_back(n);
}
cout << "Prime factors of the number are: ";
for (int i = 0; i < factors.size(); i++) {
cout << factors[i] << " ";
}
}
int main() {
int n;
cout << "Enter a number to find its prime factors: ";
cin >> n;
primeFactors(n);
return 0;
}
这是一个用于分解质因数的高效算法，首先判断2是否为n的因数，然后从3开始每次递增2判断是否为质因数，直到质因数的平方大于n为止。最后判断n是否大于2，如果是则加入质因数列表中。输出结果为输入的数的所有质因数。
