leetcode 解题思路

A company is planning to interview2npeople. Given the arraycostswherecosts[i] = [aCosti, bCosti],the cost of flying theithperson to cityaisaCosti, and the cost of flying theithperson to citybisbCosti.Returnthe minimum cost to fly every p...

Given an array ofdistinctintegersarr, find all pairs of elements with the minimum absolute difference of any two elements.Return a list of pairs in ascending order(with respect to pairs), each pair[a, b]followsa, bare fromarr a < b b - aeq...

You are given two0-indexedarrays of stringsstartWordsandtargetWords. Each string consists oflowercase English lettersonly.For each string intargetWords, check if it is possible to choose a string fromstartWordsand perform aconversion operation...

Given annx nbinarygrid, in one step you can choose twoadjacent rowsof the grid and swap them.A grid is said to bevalidif all the cells above the main diagonal arezeros.Returnthe minimum number of stepsneeded to make the grid valid, or-1if ...

Merge k Sorted Lists(这题是用PQ，或者merge sort都可以做，关于第K大的问题，参考: PriorityQueue 第K大问题总结)Sort an Array ( 重点掌握merge sort和quick sort，因为两者可以演变为很多其他的算法,divide conquer, quick select)Merge IntervalsSort ColorsSort ListConvert Sorted Array to Binary Searc...

Given a list of folders, remove all sub-folders in those folders and return inany orderthe folders after removing.If afolder[i]is located withinanotherfolder[j], it is called asub-folderof it.The format of a path isone or more concatenated str...

Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers(h, k), wherehis the height of the person andkis the number of people in front of this person who have a height greater than or equal toh. Wri...

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 is9534330.Note: The result may be very

Given an integer array, sort it in ascending order. Use selection sort, bubble sort, insertion sort or any O(n2) algorithm.ExampleExample 1: Input: [3, 2, 1, 4, 5] Output: [1, 2, 3, 4, 5] E...

Given anunsorted array, sort the given array. You are allowed to do only following operation on array.flip(arr, i): Reverse array from 0 to i Unlike a traditional sorting algorithm, which attem...

Given an array withnobjects 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 the integers 0,...

We have some permutationAof[0, 1, ..., N - 1], whereNis the length ofA.The number of (global) inversions is the number ofi < jwith0 <= i < j < NandA[i] > A[j].The number ...

Merge Sort Array: 看完stanford的 CS106B的video，https://www.youtube.com/watch?v=LlNawf0JeF0&list=PLnfg8b9vdpLn9exZweTJx44CII1bYczuk&index=55醍醐灌顶；public class Solution { /** * @param A:...

Determine whether an integer is a palindrome. Do this without extra space.Some hints:Could negative integers be palindromes? (ie, -1)If you are thinking of converting the integer to string, note

Given an unsorted array nums, reorder it in-place such thatnums[0] = nums[2] .For example, given nums = [3, 5, 2, 1, 6, 4], one possible answer is[1, 6, 2, 5, 3, 4].思路：这题主要在观察规律，并且证明算法的可行性。n

Sort Integer Array using Insertion sort.//******************************************************************************************************** /* Insertion Sort 原理：就是前面的sort部分全部是相对值，从后面拿一个元素，然...

The basic step of sorting an array are as follows:Select a pivot, normally the middle one From both ends, swap elements and make left elements < pivot and all right > pivot Recursively so...

Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input string does not contain leading or trailing spaces and the words are always