James Pan

本人原创，如有错误恳请指正，谢谢！原题网址https://leetcode.com/problems/count-complete-tree-nodes/Given a complete binary tree, count the number of nodes.

原题网址：https://leetcode.com/problems/alien-dictionary/There is a new alien language which uses the latin alphabet. However, the order among letters are unknown to you. You receive a list of words

原题网址：https://leetcode.com/problems/minimum-height-trees/For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all po

原题网址：https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the

原题网址：https://leetcode.com/problems/implement-strstr/Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.方法：KMP算法。p

原题网址：https://leetcode.com/problems/russian-doll-envelopes/You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and on

原题网址：https://leetcode.com/problems/count-of-smaller-numbers-after-self/You are given an integer array nums and you have to return a new counts array. The counts array has the property where coun

原题网址：https://leetcode.com/problems/wiggle-subsequence/A sequence of numbers is called a wiggle sequence if the differences between successive numbers strictly alternate between positive and nega

原题网址：https://leetcode.com/problems/paint-fence/There is a fence with n posts, each post can be painted with one of the k colors.You have to paint all the posts such that no more than two adj

原题网址：https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the m

原题网址：https://leetcode.com/problems/guess-number-higher-or-lower-ii/We are playing the Guess Game. The game is as follows:I pick a number from 1 to n. You have to guess which number I picked.Ev

原题网址：https://leetcode.com/problems/largest-divisible-subset/Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfie

原题网址：https://leetcode.com/problems/max-sum-of-sub-matrix-no-larger-than-k/Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is

原题网址：https://leetcode.com/problems/arithmetic-slices-ii-subsequence/A sequence of numbers is called arithmetic if it consists of at least three elements and if the difference between any two con

原题网址：https://leetcode.com/problems/optimal-account-balancing/A group of friends went on holiday and sometimes lent each other money. For example, Alice paid for Bill's lunch for $10. Then later

原题网址：https://leetcode.com/problems/unique-substrings-in-wraparound-string/Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this:

原题网址：https://leetcode.com/problems/can-i-win/In the "100 game," two players take turns adding, to a running total, any integer from 1..10. The player who first causes the running total to reach

原题网址：https://leetcode.com/problems/patching-array/Given a sorted positive integer array nums and an integer n, add/patch elements to the array such that any number in range [1, n] inclusive ca

原题网址：https://leetcode.com/problems/the-skyline-problem/A city's skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. Now suppose y

原题网址：https://leetcode.com/problems/regular-expression-matching/Implement regular expression matching with support for '.' and '*'.'.' Matches any single character.'*' Matches zero or more of

原题网址：https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary search tree.

原题网址：https://leetcode.com/problems/count-of-range-sum/Given an integer array nums, return the number of range sums that lie in [lower, upper] inclusive.Range sum S(i, j) is defined as the su

原题网址：https://leetcode.com/problems/find-the-duplicate-number/Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate nu

原题网址：https://leetcode.com/problems/h-index/Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index.Accordi

原题网址：https://leetcode.com/problems/remove-invalid-parentheses/Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results.Note: The

原题网址：https://leetcode.com/problems/create-maximum-number/Given two arrays of length m and n with digits 0-9 representing two numbers. Create the maximum number of length k  from digits of th

原题网址：https://leetcode.com/problems/course-schedule-ii/There are a total of n courses you have to take, labeled from 0 to n - 1.Some courses may have prerequisites, for example to take cour

原题网址：https://leetcode.com/problems/wiggle-sort-ii/Given an unsorted array nums, reorder it such that nums[0] nums[2] .Example:(1) Given nums = [1, 5, 1, 1, 6, 4], one possible answer is

原题网址：https://leetcode.com/problems/majority-element-ii/Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1

原题网址：https://leetcode.com/problems/median-of-two-sorted-arrays/There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run t

原题网址：https://leetcode.com/problems/water-and-jug-problem/You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine wheth

原题网址：https://leetcode.com/problems/meeting-rooms-ii/Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of confe

原题网址：https://leetcode.com/problems/shortest-palindrome/Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrom

原题网址：https://leetcode.com/problems/palindrome-partitioning-ii/Given a string s, partition s such that every substring of the partition is a palindrome.Return the minimum cuts needed for a pa

原题网址：https://leetcode.com/problems/binary-tree-inorder-traversal/Given a binary tree, return the inorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1

原题网址：https://leetcode.com/problems/reconstruct-itinerary/Given a list of airline tickets represented by pairs of departure and arrival airports [from, to], reconstruct the itinerary in order.

原题网址：https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/Given a non-empty integer array, find the minimum number of moves required to make all array elements equal, where a m