Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example,Given the following matrix: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] You should return [1,2,3,6,9,8,7,4,5]. 题目标签:Array 这道题目给了我们一个矩阵,…

Given an integer n, generate a square matrix filled with elements from 1 to n^2 in spiral order. For example,Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] 与 54. Spiral Matrix 类似,这次给定一个整数n,以螺旋顺序填充元素到n^2…

On a 2 dimensional grid with R rows and C columns, we start at (r0, c0) facing east. Here, the north-west corner of the grid is at the first row and column, and the south-east corner of the grid is at the last row and column. Now, we walk in a clockw…

1105 Spiral Matrix(25 分) This time your job is to fill a sequence of N positive integers into a spiral matrix in non-increasing order. A spiral matrix is filled in from the first element at the upper-left corner, then move in a clockwise spiral. The…

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example,Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] 依旧是dfs问题,代码如下所示: class Solution { public: vecto…

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example,Given the following matrix: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] You should return [1,2,3,6,9,8,7,4,5]. 典型的dfs问题,与前面一个问题比较像,代码如下…

[059-Spiral Matrix II(螺旋矩阵II)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example, Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8…

[139-Word Break(单词拆分)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given 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, given s = "leetcode", di…

[053-Maximum Subarray(最大子数组和)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4], the contiguous subarr…

[062-Unique Paths(唯一路径)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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…

[136-Single Number(仅仅出现一次的数字)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given an 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 w…

[075-Sort Colors (颜色排序)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use th…

[101-Symmetric Tree(对称树)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following is…

[109-Convert Sorted List to Binary Search Tree(排序链表转换成二叉排序树)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 题目大意 给定一个升序的单链表.将它转换成一颗高度平衡的二叉树 解题思路 解法…

[015-3 Sum(三个数的和)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Note: Elements in a triplet (a,b,c)…

[030-Substring with Concatenation of All Words(串联全部单词的子串)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concate…

[114-Flatten Binary Tree to Linked List(二叉树转单链表)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a binary tree, flatten it to a linked list in-place. For example, Given 1 / \ 2 5 / \ \ 3 4 6 The flattened tree should look like: 1 \ 2 \ 3 \ 4 \ 5 \ 6 题目…

[118-Pascal's Triangle(帕斯卡三角形(杨辉三角))] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 题目大意 给定一个正整数n,求n层帕斯卡三角…

[010-Regular Expresssion Matching(正則表達式匹配)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element.The matching sh…

[079-Word Search(单词搜索)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontall…

[066-Plus One(加一)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a non-negative number represented as an array of digits, plus one to the number. The digits are stored such that the most significant digit is at the head of the list. 题目大意 给定一个用数组表示的一个数…

[067-Add Binary(二进制加法)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given two binary strings, return their sum (also a binary string). For example, a = "11" b = "1" Return "100" 题目大意 给定两个二进制的字符串,返回它们的和,也是二进行制字符串. 解题思路 先将相应的两个二进制字符…

[120-Triangle(三角形)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given 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 [ [2], [3,4], [6,5,7], […

[056-Merge Intervals(区间合并)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a collection of intervals, merge all overlapping intervals. For example, Given [1,3],[2,6],[8,10],[15,18], return [1,6],[8,10],[15,18]. 题目大意 给定一个区间集合,合并有重叠的区间. 解题思路 先对区间进行排序.按開始…

[033-Search in Rotated Sorted Array(在旋转数组中搜索)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search.…

[145-Binary Tree Postorder Traversal(二叉树非递归后序遍历)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive sol…

[168-Excel Sheet Column Title(Excell列标题)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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 -> AB…

[058-Length of Last Word (最后一个单词的长度)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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…

[129-Sum Root to Leaf Numbers(全部根到叶子结点组组成的数字相加)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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 represent…

[064-Minimum Path Sum(最小路径和)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 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…