原创 【Leetcode】Two Sum II #Too easy, just review hashmap
Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a spec
2020-07-03 05:05:20
原创 【Leetcode】LRU Cache
Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations:
2020-07-03 05:05:20
原创 【Leetcode】Sliding Window Maximum
Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very r
2020-07-03 05:05:18
原创 【Leetcode】Rectangle Area && Classic Prob: Overlap Rectangle
Overlap Rectangle: 這道題的關鍵在於：不要去考慮overlap有幾種情況，雖然肯定能做出來，但是要考慮的情況太多了，不如就考慮一定不會overlap的情況。無非就是兩個rectangle x軸離的太遠或者y軸離得太遠
2020-07-03 05:05:18
原创 【Leetcode】Binary Tree Level Order Traversal II
Very classic question and one of the hardest one I've met recently!!! The solution is also very clever and impressive!
2020-02-23 11:12:17
原创 【Leetcode】Subsets
Given a set of distinct integers, nums, return all possible subsets. Note: Elements in a subset must be in non-desc
2020-02-23 11:12:17
原创 【Leetcode】Search a 2D Matrix II
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
2020-02-23 11:12:17
原创 【Leetcode】Rotate Image
You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Coul
2020-02-23 11:12:17
原创 【Leetcode】Validate Binary Search Tree
Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The lef
2020-02-23 11:12:17
原创 【Leetcode】Longest palindrome substring
Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000,
2020-02-23 11:12:17
原创 【Leetcode】Maximum Size Subarray Sum Equals k
Example 1: Given nums = [1, -1, 5, -2, 3], k = 3, return 4. (because the subarray [1, -1, 5, -2] sums to 3 and is th
2020-02-23 11:12:17
原创 【Leetcode】Kth Smallest Element in a BST
Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. Note: You may assu
2020-02-23 11:12:17
原创 碰到一道經典的，Max Min Path
題目大概是這個意思：給定一個n*m的數組，找到每一條能從左上角探索到左下角的path，然後每一條path裏找到最小值，所有這些最小值合在一起，看最大值是哪個。 舉個例子： [8, 4, 7] [6, 5, 9] 有3條path： 8-4
2020-02-23 11:12:17
原创 【Leetcode】Reverse LinkedList
太經典的題目了，我就不廢話了，只是爲了po這個我非常obsessed的方法： /** * Definition for singly-linked list. * public class ListNode { * int
2020-02-23 11:12:17
原创 Reverse Half LinkedList
1-2-3-4-5-6 into 1-2-3-6-5-4 or 1-2-3-4-5 into 1-2-5-4-3 I took advantage of reversing a linkedlist. I provided main fu
2020-02-23 11:12:17