java 368.最大的可分子集（＃1）.java

Posted 2021-05-08

class Solution {
    public List<Integer> largestDivisibleSubset(int[] nums) {
        List<Integer> res = new ArrayList<>();
        if (nums == null || nums.length < 1) return res;
        int len = nums.length;
        Arrays.sort(nums);
        int[] dp = new int[len];
        int[] pre = new int[len];
        int max = 1;
        int maxIdx = 0;
        dp[0] = 1;
        pre[0] = -1;
        for (int i = 1; i < len; i++) {
            pre[i] = -1;
            dp[i] = 1;
            for (int j = i - 1; j >= 0; j--) {
                if (nums[i] % nums[j] == 0) {
                    //dp[i] = Math.max(dp[i], dp[j] + 1);
                    if (dp[j] + 1 > dp[i]) {
                        pre[i] = j;
                        dp[i] = dp[j] + 1;
                    }
                }
            }
            if (dp[i] >= max) {
                max = dp[i];
                maxIdx = i;
            }
        }
        
        Integer[] ans = new Integer[max];
        while (maxIdx != -1) {
            ans[--max] = nums[maxIdx];
            maxIdx = pre[maxIdx];
        }
        
        return Arrays.asList(ans);
        
        
    }
}