Largest Divisible Subset

Java

public class Solution {
    /*
     * @param nums: a set of distinct positive integers
     * @return: the largest subset 
     */
    public List<Integer> largestDivisibleSubset(int[] nums) {
        // write your code here
        Arrays.sort(nums);
        int n = nums.length;
        
        int[] dp = new int[n];
        int[] pre = new int[n];
        
        for(int i = 0; i < n; i ++){
            dp[i] = 1;
            pre[i] = -1;
        }
        
        int max = 0;
        int index = -1;
        for(int i = 0; i < n; i ++){
            for(int j = 0; j < i; j ++){
                if(nums[i] % nums[j] == 0 && dp[i] < dp[j] + 1){
                    dp[i] = dp[j] + 1;
                    pre[i] = j;
                }
            }
            if(dp[i] >= max){
                max = dp[i];
                index = i;
            }
        }
        List<Integer> res = new ArrayList<>();
        for(int i = 0; i < max; i ++){
            res.add(nums[index]);
            index = pre[index];
        }
        
        return res;
    }
}