FightForProgrammer的专栏

LeetCode Word BreakGiven a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words.For example, givens = "l

Partition List Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.You should preserve the original relative order of

Construct Binary Tree from Preorder and Inorder TraversalGiven preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the t

LeetCode Repeated DNA SequencesAll DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful to identify repe

LeetCode Min StackDesign a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of

LeetCode ：Binary Tree Maximum Path SumGiven a binary tree, find the maximum path sum.The path may start and end at any node in the tree.For example:Given the below binary tree,

LeetCode Rotate ArrayRotate Array Total Accepted: 5488 Total Submissions: 29811 My Submissions Question Solution Rotate an array of n elements to the right by k steps.For example, with n = 7

LeetCode Rotate ImageYou are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Follow up:Could you do this in-place?关键地方在于就地。而不用新的内存。

LeetCode TriangleGiven a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given the following triangle[

LeetCode Unique Binary Search Trees I   IIⅠ第一题主要用到了数学推导的方法。令数组arr[i]表示i个节点时BST的数目。则arr[0]=arr[1]=1，arr[2] = 2.对于已知的arr[0...n]求arr[n+1]，此n+1个节点中有个是根节点，令它的左子树个数L(n)，右子数节点个数R(n)，则左子树有arr[L(n)]中

Distinct SubsequencesGiven a string S and a string T, count the number of distinct subsequences of T in S.A subsequence of a string is a new string which is formed from the original string b

LeetCode House RobberYou are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of

LeetCode Maximal SquareGiven a 2D binary matrix filled with 0's and 1's, find the largest square containing all 1's and return its area.For example, given the following matrix:1 0 1 0 01

LeetCode Implement Trie (Prefix Tree)Implement a trie with insert, search, and startsWith methods.Note:You may assume that all inputs are consist of lowercase letters a-z.题目要求是实现字典

Given two words (beginWord and endWord), and a dictionary, find the length of shortest transformation sequence from beginWord to endWord, such that:Only one letter can be changed at a timeEach int

Contains Duplicate II   Contains Duplicate III一、Contains Duplicate II Given an array of integers and an integer k, find out whether there there are two distinct indices i and j in the

LeetCode Course ScheduleThere 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 course 0 you have to first take co

LeetCode Word Search IIGiven a 2D board and a list of words from the dictionary, find all words in the board.Each word must be constructed from letters of sequentially adjacent cell, where "

Add and Search Word - Data structure design Design a data structure that supports the following two operations:void addWord(word)bool search(word)search(word) can search a literal word o

LeetCode Minimum Size Subarray SumGiven an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn't one, return 0 inste

LeetCode LRU CacheDesign and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set.get(key) - Get the value (will always be

LeetCode Gray CodeThe gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integer n representing the total number of bits in the code

Best Time to Buy and Sell Stock I II IIII对于第一题，本质意义是求出数组中某两个元素（day[i],day[i]）的最大差值。但是，要求j>iint maxProfit(vector &prices) { if(prices.size() ==0) return 0;

LeetCode Recover Binary Search TreeTwo elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A solution using O(n) space is

Find Minimum in Rotated Sorted Array

LeetCode Gas StationGas Station  There are N gas stations along a circular route, where the amount of gas at station i is gas[i].You have a car with an unlimited gas tank and it cost

LeetCode:Reorder ListGiven 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,Given {1

LeetCode:Sort ListSort a linked list in O(n log n) time using constant space complexity.

LeetCode Longest Consecutive Sequence

LeetCode : Insertion Sort ListInsertion Sort List Sort a linked list using insertion sort.

LeetCode:Count and SayThe 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

LeetCode--isSameTree

LeetCode Sum Root to Leaf Numbers

LeetCode Maximum Product Subarray

LeetCode Convert Sorted List to Binary Search TreeConvert Sorted List to Binary Search Tree Given a singly linked list where elements are sorted in ascending order, convert it to a heigh

LeetCode Populating Next Right Pointers in Each NodeGiven a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; }

LeetCode Flatten Binary Tree to Linked ListGiven a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6

LeetCode Longest Palindromic SubstringGiven a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest pa

LeetCode PermutationsGiven a collection of numbers, return all possible permutations.For example,[1,2,3] have the following permutations:[1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2],

LeetCode N-QueensThe 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 t