peterkang202的专栏

Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).For example: Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \

The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, …1 is read off as “one 1” or 11. 11 is read off as “two 1s” or 21. 21 is read off as “one 2, the

Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers such that they add up to the target, where in

class Solution { public: bool isIsomorphic(string s, string t) { if(s.empty() && t.empty()) return true; int sl = s.length(); int tl = t.length(); char *

LeetCode:Reorder List 题目（题目链接）： Given a singly linked list L: L0→L1→…→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example, G

Implement a basic calculator to evaluate a simple expression string.The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty space

The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other. Given an integer n, return all distinct solutions to the n-queens puzzle.

题目链接：(https://leetcode.com/problems/the-skyline-problem/)示例代码：public class Solution { public List<int[]> getSkyline(int[][] buildings) { List<int[]> res = new ArrayList<int[]>(); Pr