leetcode264 Ugly Number II

1 class Solution
2 {
3 public:
4     int nthUglyNumber(int n)
5     {
6         vector<int> dp(n);
7         dp[0] = 1;
8         int p2 = 0, p3 = 0, p5 = 0;
9         for (int i = 1; i < n; i++)
10         {
11             dp[i] = min(dp[p2] * 2, min(dp[p3] * 3, dp[p5] * 5));
12             if (dp[i] == dp[p2] * 2) p2++;
13             if (dp[i] == dp[p3] * 3) p3++;
14             if (dp[i] == dp[p5] * 5) p5++;
15         }
16         return dp[n - 1];
17     }
18 };