Insertion Sort ListQuestionSort a linked list using insertion sort. Analysis An easy and clear way to sort ( O(1) space ) Code1234567891011121314151617181920212223242526272829/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(i ...

Reverse IntegerQuestionReverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 Analysis越界判断： tmp加上tail后看是否还能变回原来的数字，不可直接利用int型的加和来判断越界（tmp*10+tail>Integer.MAX_VALUE） Code12345678910111213141516171819public class Solution { public int reverse(int x)  ...

House RobberQuestionYou 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 them is that adjacent houses have security system connected and it will automatically contact the police if ...

Majority ElementQuestionGiven an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. Analysis Boyer-Moore Majority 直接Array排序后找最多会超时 Code12 ...

Course ScheduleQuestionThere 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: [0,1] Given the total number of courses and a list of prerequisite pairs, ...

Binary WatchQuestionA binary watch has 4 LEDs on the top which represent the hours (0-11), and the 6 LEDs on the bottom represent the minutes (0-59). Each LED represents a zero or one, with the least significant bit on the right. For example, the above binary watch reads “3:25”. Given a non-negative ...

Trapping Rain Water IIQuestionGiven an m x n matrix of positive integers representing the height of each unit cell in a 2D elevation map, compute the volume of water it is able to trap after raining. Note:Both m and n are less than 110. The height of each unit cell is greater than 0 and is less than ...

Product of Array Except SelfQuestionGiven an array of n integers where n > 1, nums, return an array outputsuch 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 example, given [1,2,3,4], return [24,12,8,6]. Analysis LeetC ...

Expression Add OperatorsQuestionGiven a string that contains only digits 0-9 and a target value, return all possibilities to add binary operators (not unary) +, -, or * between the digits so they evaluate to the target value. Examples: 12345"123", 6 -> ["1+2+3", "123&quo ...

Max Points on a LineQuestionGiven n points on a 2D plane, find the maximum number of points that lie on the same straight line. Analysis 九章算法 map.put((double)Integer.MIN_VALUE,1); 可能整个序列都是相同点，他们的斜率用MIN_VALUE表示 利用dup变量记录有多少个重复的点 每次进入一个新的坐标点比较的时候记住map.clear 计算key的时候必须+0.0，否则无法通过所有点纵坐标相同的情况 Code1234 ...