leetcode 超级丑数

 

 

个人感觉做这道题如果没有之前做过一些其他丑数题的经历还是比较吃力的，贴个官方解法。

 

 

 

class Solution {
    public int nthSuperUglyNumber(int n, int[] primes) {
        int[] dp = new int[n + 1];
        dp[1] = 1;
        int m = primes.length;
        int[] pointers = new int[m];
        Arrays.fill(pointers, 1);
        for (int i = 2; i <= n; i++) {
            int[] nums = new int[m];
            int minNum = Integer.MAX_VALUE;
            for (int j = 0; j < m; j++) {
                nums[j] = dp[pointers[j]] * primes[j];
                minNum = Math.min(minNum, nums[j]);
            }
            dp[i] = minNum;
            for (int j = 0; j < m; j++) {
                if (minNum == nums[j]) {
                    pointers[j]++;
                }
            }
        }
        return dp[n];
    }
}