Description

Submission

class Solution {
public:
    int nthUglyNumber(int n) {
        int i = 0, j = 0, k = 0;
        vector<int> rets{1};

        for(int t = 0; t < n - 1; ++t) {
            int cur = min(rets[i] * 2, min(rets[j] * 3, rets[k] * 5));
            rets.push_back(cur);

            if(cur == rets[i] * 2) ++i;
            if(cur == rets[j] * 3) ++j;
            if(cur == rets[k] * 5) ++k;
        }

        return rets.back();
    }
};

class Solution {
    typedef long long ll;
public:
    int nthUglyNumber(int n) {
        vector<ll> numbers;
        vector<ll> factors{2, 3, 5};
        set<ll> Set;
        Set.insert(1);

        for(int i = 0; i < n; ++i) {
            int cur = *Set.begin();
            Set.erase(Set.begin());
            numbers.push_back(cur);

            for(auto x: factors) {
                Set.insert(x * cur);
            }
        }
        
        return numbers[n-1];
    }
};