69. Sqrt(x)
Implement int sqrt(int x). Compute and return the square root of x. 思路： 这道题不难，用binary search 1-x就行，有…
162. Find Peak Element
A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠…
287. Find the Duplicate Number
Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), pro…
142. Linked List Cycle II
Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Note…
49. Group Anagrams
Given an array of strings, group anagrams together. For example, given: [“eat”, “tea”, “tan”, “ate”,…
Queue & Stack解题方法小结
LeetCode上的相关题目(easy) 155, 225, 232, 346 常用方法 Stack: push(), pop(), peak(), empty() Queue(LinkedList)…
346. Moving Average from Data Stream
Given a stream of integers and a window size, calculate the moving average of all integers in the sl…
155. Min Stack
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. pu…
225. Implement Stack using Queues
Implement the following operations of a stack using queues. push(x) — Push element x onto stac…
232. Implement Queue using Stacks
Implement the following operations of a queue using stacks. push(x) — Push element x to the ba…