The kth Factor of n (the kth factor of C++n)

Problem-solving ideas:

(1) Sequential judgment

class Solution {
public:
    int kthFactor(int n, int k) {
        vector<int> v;
        for(int i=1;i<=n;i++) {
            if(n%i==0) v.push_back(i);
        }
        if(v.size()<k) return -1;
        else return v[k-1];
    }
};