264. Ugly Number II

class Solution {
    public int nthUglyNumber(int n) {
        int[] dp = new int[1690];
        dp[0] = 1;
        int i2 = 0, i3 = 0, i5 = 0;
        
        for (int i = 1; i < 1690; i++) {
            int tmp2 = dp[i2] * 2, tmp3 = dp[i3] * 3, tmp5 = dp[i5] * 5;
            dp[i] = tmp2;
            if (tmp3 < dp[i]) {
                dp[i] = tmp3;
            }
            
            if (tmp5 < dp[i]) {
                dp[i] = tmp5;
            }
            
            if (dp[i] == tmp2) {
                i2++;
            }
            if (dp[i] == tmp3) {
                i3++;
            }
            if (dp[i] == tmp5) {
                i5++;
            }
        }
        
        return dp[n - 1];
    }
}