Ghost In Matrix

题目描述 有一个整数数组，请编写一个函数，找出索引m和n，只要将m和n之间的元素排好序，整个数组就是有序的。注意：n-m应该越小越好，也就是说，找出符合条件的最短序列。 给定一个int数组A和数组的大小n，请返回一个二元组，代表所求序列的起点和终点。(原序列位置从0开始标号,若原序列有序，返回[0,0])。保证A中元素均为正整数。 测试样例： [1,4,6,5,9,10],6

题目：You 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?思路：首先，要求原地调整，那么需要寻找变换规律。举个例子：对于3x3的矩阵，如顺

题目：Given 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], and [3,2,1].思路：递

题目：Given a string s, partition s such that every substring of the partition is a palindrome.Return the minimum cuts needed for a palindrome partitioning of s.For example, given s = "aab"

题目：Given an unsorted integer array, find the first missing positive integer.For example,Given [1,2,0] return 3,and [3,4,-1,1] return 2.Your algorithm should run in O(n) time and uses

题目：Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangement is not possible, it must rearrange it as the lowest

题目：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 costs cost[i] of gas to travel from statio

题目：Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.De

题目：Given a collection of intervals, merge all overlapping intervals.For example,Given [1,3],[2,6],[8,10],[15,18],（原始区间）return [1,6],[8,10],[15,18].（最终区间）思路：该题是一道极角排序的类似题目。我们可以使用O（n）复

题目：Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.The Sudoku board could be partially filled, where empty cells are filled with the character '.'.A partia

题目：Given 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 palindromic substring.思路：1000之内

Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.

题目：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).Find the minimum element.The array may contain dup

题目Count Complete Tree Nodes Given a complete binary tree, count the number of nodes.In a complete binary tree every level, except possibly the last, is completely filled, and all nodes in the last lev

题目Description:Count the number of prime numbers less than a non-negative number, n.方法对于这道题，最简单最直观的方法往往是：对n以下的每一个数字进行判断从而求出个数。而在对每个数字（比如x）判断的时候，又是暴力验证的思想，即从2开始一直到sqrt（x）进行相除判断是否整除。更有甚者直接从2到x/2或

题目Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window

题目Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].Solve it without division and in O(n).For

题目Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.思路这一次说的是一个普通的二叉树，给出两个节点，求他们的最低公共父节点。 回想一下，当这棵二叉树是二分查找树的时候的解决方案： 二分查找树解法：http://blog.youkuaiyun.com/langduhualangd

题目Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.思路题目要求一个二叉排序树的两个节点的公共父节点，说通俗点，其实就是这两个节点所在的分支是从哪里开始分叉的。求出这个分叉点。对于二叉排序树，它的一个特点就是：一个节点的左子树节点都小于该节点，而

题目：Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)You have the following 3 operations permitted on

题目：The demons had captured the princess (P) and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of M x N rooms laid out in a 2D grid. Our valiant knight (K) was in

题目：Given an integer n, return the number of trailing zeroes in n!.Note: Your solution should be in logarithmic time complexity.思路：在1到n这些数字中，能够贡献多少个因子5，就有多少个0.因为0是由10得到的，而10=2*5；显然2的数量远

题目：Given a list of non negative integers, arrange them such that they form the largest number.For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.Note: The result ma

题目：A peak element is an only element that is greater than its neighbors.Given an input array where num[i] ≠ num[i+1], find a peak element and return its index.The array may contain multi

题目：Given 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 by deleting some (c

题目:A message containing letters from A-Z is being encoded to numbers using the following mapping:'A' -> 1'B' -> 2...'Z' -> 26Given an encoded message containing digits, determine the t

题目：Given a string s1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible representation of s1 = "great": great

题目：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

题目：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

Design 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 positive) of the key if

Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3

题目：Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end should remain

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially sorted according to their start times.E

Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never diffe

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree and sum = 22, 5 / \

题目：Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.Each number in C may only be used once in th

The 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, print the sequence of

题目：Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:"((()))", "(()())", "(())()", "()(()

题目：Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i,

题目：Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note: