JUNE DIARY

问题一：LeetCode 53. Maximum Subarray求最小和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,

先看一下这个问题：LeetCode 55. Jump GameQuestionGiven an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents yo

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 the integers

/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */public class Solution { public ListNode addT

动态规划问题通过利用重叠子问题，优化子结构，以空间换时间，来达到优化时间复杂度的目的。分类主要分为两大类：自顶向下Top-down(经常被称作：memorization);  自底向上Bottom-Up.一、memoization（TOp-Down）:例如求斐波那契数列fib(5),过程如下：相同的计算过程一直再重复，为了避免重复，我们可以把已经计算过的结果

Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.我的思路：暴力方法，简单直接。从字符串haystack的第一个字符开始，从左至右依次匹配它的子串（同needle比较）。

分类 ：Tree; BFS; DFS 问题描述：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

分类：Tree ；DFS问题描述：Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical and the nodes have the

分类： Array ; Two Points问题描述：Given an array and a value, remove all instances of that value in place and return the new length.Do not allocate extra space for another array, you must do this