原创 java源碼學習----ArrayList
ArrayList源碼分析 類的繼承關係 ArrayList的默認大小爲10 ArrayList的底層實現 構造函數 1 無參構造函數 2 指定大小的構造函數 3 利用集合構造 常用函數 1 size求大小 2 isEmp
2020-07-03 10:28:51
原创 [Leetcode] 436. Find Right Interval
leetcode題目 題意：給定一組區間，求給定區間 在這些區間中 在給定區間右側，且與給定區間距離最近區間的位置。 思路： 把給定區間的右邊界與這些區間中的左邊界進行比較，選擇出，左邊界比給定區間右邊界大,且距給定區間最近區
2020-07-03 10:28:51
原创 [leetcode] 107. Binary Tree Level Order Traversal II
Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, leve
2020-02-23 09:35:47
原创 [leetcode] 101. Symmetric Tree
題目： leetcode 鏈接 思路：分別判斷對稱位置的值是否相同，即根節點的左子樹的左節點和右子樹的右節點 與 左子樹的右節點和右子樹的左節點是否都相同。並依次按左子樹的左節點和右子樹的右節點 左子樹的右節點和右子樹的左節
2020-02-23 09:35:47
原创 [Leetcode] 319. Bulb Switcher
題目: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bu
2020-02-23 09:35:47
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原创 [Leetcode] 60. Permutation Sequence
題目： The set [1,2,3,…,n] contains a total of n! unique permutations. By listing and labeling all of the permutation
2020-02-23 09:35:47
原创 [Leetcode] 226. Invert Binary Tree
題目： Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \
2020-02-23 09:35:47
原创 [leetcode] 198. House Robber
題目： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money
2020-02-23 09:35:47
原创 [Leetcode] 350. Intersection of Two Arrays II
題目： Given two arrays, write a function to compute their intersection. Example: Given nums1 = [1, 2, 2, 1], nums2
2020-02-23 09:35:47
原创 [Leetcode] 49. Group Anagrams
題目： 鏈接 Group Anagrams Given an array of strings, group anagrams together. For example, given: [“eat”, “tea”, “tan
2020-02-23 09:35:47
原创 [leetcode] 121. Best Time to Buy and Sell Stock
題目： Say you have an array for which the ith element is the price of a given stock on day i. If you were only permi
2020-02-23 09:35:47
原创 Collection 集合大家族
轉載來自 http://www.cnblogs.com/chenssy/p/3495238.html java集合大家族 一Collection接口 二List接口 1ArrayList 2LinkedList 3Vect
2020-02-23 09:35:47
原创 [leetcode] 96. Unique Binary Search Trees
題目： Given n, how many structurally unique BST’s (binary search trees) that store values 1…n? For example, Given n
2020-02-23 09:35:47
原创 [leetcode] 376. Wiggle Subsequence
題目： A sequence of numbers is called a wiggle sequence if the differences between successive numbers strictly altern
2020-02-23 09:35:47
原创 [leetcode] 122. Best Time to Buy and Sell Stock II
題目： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to
2020-02-23 09:35:47