1691. Maximum Height by Stacking Cuboids

//O(n^2) time and O(n) space
class Solution {
    public int maxHeight(int[][] cuboids) {
        int n = cuboids.length;
        for (int[] cube : cuboids) {
            Arrays.sort(cube);
        }
        Arrays.sort(cuboids, new Comparator<int[]>() {
            public int compare(int[] a, int[] b) {
                if (a[0] != b[0])
                    return b[0] - a[0];
                if (a[1] != b[1])
                    return b[1] - a[1];
                return b[2] - a[2];
            }
        });
        int ans = 0;
        int[] dp = new int[n];
        for(int i = 0; i < n; i++){
            dp[i] = cuboids[i][2];
            for(int j = 0; j < i; j++){
                if(cuboids[j][0] >= cuboids[i][0] && cuboids[j][1] >= cuboids[i][1] && cuboids[j][2] >= cuboids[i][2]){
                    dp[i] = Math.max(dp[i], dp[j] + cuboids[i][2]);
                }
            }
            ans = Math.max(ans, dp[i]);
        }
        return ans;
    }
}