class Solution {
public:
int getUglyNumber(int n) {
vector<int> q(1, 1);
int i = 0, j = 0, k = 0;
while(-- n)
{
int t = min(q[i] * 2, min(q[j] * 3, q[k] * 5));
q.push_back(t);
if(q[i] * 2 == t) i ++ ;
if(q[j] * 3 == t) j ++ ;
if(q[k] * 5 == t) k ++ ;
}
return q.back();
}
};