linglingconglin-优快云博客

原创 58. Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is defin...

2018-08-29 08:52:15 211

原创 54. Spiral Matrix

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.Example 1:Input:[ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ]]Output: [1,2,3,6,9,8,7,4,5]...

2018-08-28 10:41:33 183

原创 263. Ugly Number

Write a program to check whether a given number is an ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.Example 1:Input: 6Output: trueExplanation: 6 = 2 ×...

2018-08-28 09:13:13 194

Write an algorithm to determine if a number is "happy".A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares o...

2018-08-28 09:04:05 165

原创 141. Linked List Cycle

Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?方法1：要求空间复杂度为O(1),建立快慢指针，如果两指针相遇说明有环/** * Definition for singly-linked list. * stru...

2018-08-28 08:39:52 138

原创 88. Merge Sorted Array

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.Note:The number of elements initialized in nums1 and nums2 are m and n respectively. You may assume tha...

2018-08-28 08:12:02 129

原创 53. Maximum Subarray

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.Example:Input: [-2,1,-3,4,-1,2,1,-5,4],Output: 6Explanati...

2018-08-28 03:58:48 131

原创 221. Maximal Square

Given a 2D binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.Example:Input: 1 0 1 0 01 0 1 1 11 1 1 1 11 0 0 1 0Output: 4方法1：动态规划重要...

2018-08-26 03:10:37 137

原创 701. Insert into a Binary Search Tree

Given the root node of a binary search tree (BST) and a value to be inserted into the tree, insert the value into the BST. Return the root node of the BST after the insertion. It is guaranteed that th...

2018-08-24 15:45:36 367

原创 739. Daily Temperatures

Given a list of daily temperatures, produce a list that, for each day in the input, tells you how many days you would have to wait until a warmer temperature. If there is no future day for which this ...

2018-08-24 11:37:52 145

原创 56. Merge Intervals

Given a collection of intervals, merge all overlapping intervals.Example 1:Input: [[1,3],[2,6],[8,10],[15,18]]Output: [[1,6],[8,10],[15,18]]Explanation: Since intervals [1,3] and [2,6] overlaps...

2018-08-24 10:14:32 129

原创 215. Kth Largest Element in an Array

Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element.Example 1:Input: [3,2,1,5,6,4] and k = 2Output: 5E...

2018-08-23 14:25:26 124

原创 207. Course Schedule

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 course 0 you have to first take course 1, which is expressed as a pair...

2018-08-23 10:44:34 135

原创 127. Word Ladder

Given two words (beginWord and endWord), and a dictionary's word list, find the length of shortest transformation sequence from beginWord to endWord, such that:Only one letter can be changed at a ti...

2018-08-21 15:05:26 270

原创 191. Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of '1' bits it has (also known as the Hamming weight).Example 1:Input: 11Output: 3Explanation: Integer 11 has binary repre...

2018-08-13 01:36:28 129

原创 300. Longest Increasing Subsequence

Given an unsorted array of integers, find the length of longest increasing subsequence.Example:Input: [10,9,2,5,3,7,101,18]Output: 4 Explanation: The longest increasing subsequence is [2,3,7,10...

2018-08-12 15:46:20 140

原创 131. Palindrome Partitioning

Given a string s, partition s such that every substring of the partition is a palindrome.Return all possible palindrome partitioning of s.Example:Input: "aab"Output:[ ["aa","b"], ["a","a"...

2018-08-12 04:39:54 147

原创 139. Word Break

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of one or more dictionary words.Note:The ...

2018-08-12 01:30:51 154

原创 129. Sum Root to Leaf Numbers

Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.An example is the root-to-leaf path 1->2->3 which represents the number 123.Find the tota...

2018-08-11 05:44:49 126

原创 118. Pascal's Triangle

Given a non-negative integer numRows, generate the first numRows of Pascal's triangle.In Pascal's triangle, each number is the sum of the two numbers directly above it.Example:Input: 5Output:...

2018-08-10 15:48:29 400

原创 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, level by level from leaf to root).For example:Given binary tree [3,9,20,null,null,15,7...

2018-08-10 13:29:19 116

原创 101. Symmetric Tree

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / \3 4 4 3B...

2018-08-10 12:15:54 112

原创 83. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.Example 1:Input: 1->1->2Output: 1->2Example 2:Input: 1->1->2->3->3Output: 1-...

2018-08-10 04:36:24 118

原创 66. Plus One

Given a non-empty array of digits representing a non-negative integer, plus one to the integer.The digits are stored such that the most significant digit is at the head of the list, and each element...

2018-08-10 04:17:33 177

原创 168. Excel Sheet Column Title

Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B 3 -> C ... 26 -> Z 27 -> AA 28 -&g...

2018-07-30 07:02:05 115

原创 171. Excel Sheet Column Number

Given a column title as appear in an Excel sheet, return its corresponding column number.For example: A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> ...

2018-07-30 06:06:11 107

原创 172. Factorial Trailing Zeroes

Given an integer n, return the number of trailing zeroes in n!.Example 1:Input: 3Output: 0Explanation: 3! = 6, no trailing zero.Example 2:Input: 5Output: 1Explanation: 5! = 120, one trai...

2018-07-30 05:51:30 130

原创 833. Find And Replace in String

To some string S, we will perform some replacement operations that replace groups of letters with new ones (not necessarily the same size).Each replacement operation has 3 parameters: a starting ind...

2018-07-28 02:00:57 235

原创 674. Longest Continuous Increasing Subsequence

Given an unsorted array of integers, find the length of longest continuous increasing subsequence (subarray).Example 1:Input: [1,3,5,4,7]Output: 3Explanation: The longest continuous increasing ...

2018-07-26 21:17:58 127

原创 860. Lemonade Change

At a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you, and order one at a time (in the order specified by bills).Each customer will only buy one lemonade a...

2018-07-26 17:50:41 104

原创 859. Buddy Strings

Example 1:Input: A = "ab", B = "ba"Output: trueExample 2:Input: A = "ab", B = "ab"Output: falseExample 3:Input: A = "aa", B = "aa"Output: trueExample 4:Input: A = "aaa

2018-07-26 00:38:49 192

原创 Submission Detail

Given a binary tree, return all root-to-leaf paths.Note: A leaf is a node with no children.Example:Input: 1 / \2 3 \ 5Output: ["1->2->5", "1->3"]Explanation: All roo...

2018-07-25 01:06:22 2195

原创 260. Single Number III

Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once.Example:Input: [1,2,1,...

2018-07-25 00:12:03 103

原创 136. Single Number

Given a non-empty array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without us...

2018-07-24 23:29:18 106

原创 299. Bulls and Cows

You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your friend makes a guess, you provide a hint tha...

2018-07-24 23:02:02 111

原创 200. Number of Islands

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume...

2018-07-24 20:55:25 135

原创 116. Populating Next Right Pointers in Each Node

Given a binary treestruct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next;}Populate each next pointer to point to its next right node. If there is no next right...

2018-07-20 23:19:59 87

原创 64. Minimum Path Sum

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at a...

2018-07-19 18:31:15 89

原创 62. Unique Paths

A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the bo...

2018-07-19 18:10:42 97

原创 43. Multiply Strings

Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.Example 1:Input: num1 = "2", num2 = "3"Output: "6"Exampl...

2018-07-19 17:37:25 126

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