摘要：用max heap // use maxHeap. Put entry into maxHeap so we can always poll a number with largest frequency public class Solution { public List<Integer> to 阅读全文

摘要：太麻烦了只好用Backtracking public List<List<Integer>> fourSum(int[] nums, int target) { List<List<Integer>> ans = new ArrayList<List<Integer>>(); if(nums == 阅读全文

摘要：参考：https://www.geeksforgeeks.org/print-all-root-to-leaf-paths-of-an-n-ary-tree/ // Java program for the above approach import java.util.ArrayList; cla 阅读全文