Aaron92的博客

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is giv...

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 / \ 2 2 / \ / \3 4 4 3B

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 linei is at (i, ai) and (i, 0). Find

Given an array of integers sorted in ascending order, find the starting and ending position of a given target value.Your algorithm's runtime complexity must be in the order of O(log n).If the ta

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.这道算法涉及到什么卡特兰数，我们把他考虑成一个树的剪枝问题，确定剪枝的条件，就是剩余的左括号树一定大于右括号数。本文算法，采纳自这篇大牛博客，详细解释，请跳转http://blo

Given a string, find the length of the longest substring without repeating characters.Examples:Given "abcabcbb", the answer is "abc", which the length is 3.Given "bbbbb", the answer is "b", with

public class Solution { public int removeElement(int[] nums, int val) { int count = 0; int result = 0; int s = nums.length; int j = 0; for(int i = 0 ; i < n

public class Solution { public int maxSubArray(int[] nums) { int count = 0; int max = nums[0]; for(int i = 0;i < nums.length;i++){ count = nums[i];

小白笔记———————（算法总结）（1）二分搜索算法解决问题：从数组中查找已知存在的数的位置前提条件：一个已经排好序的整型数组一般解决方式：遍历数组，找到第一次出现的要找的数，返回它的位置使用价值：除非特别指定用二分搜索算法，大部分情况下都能用一层循环解决求众数解决问题：求整型数组中出现次数最多的数一般解决方法：用一个数组记录每个数出现的次数，遍历这个数组找到最大值，返回原数组该位置的

Given a string containing just the characters '(', ')','{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the correct order, "()" and "()[]{}" are all valid b

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

Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321click to show spoilers.Have you thought about this?Here are some good questions to ask before coding.

Implement atoi to convert a string to an integer.Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input case

Given a set of candidate numbers (C)(without duplicates) and a target number (T), find all unique combinations inC where the candidate numbers sums to T.The same repeated number may be chosen

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

Reverse bits of a given 32 bits unsigned integer.Example:Input: 43261596 Output: 964176192 Explanation: 43261596 represented in binary as 00000010100101000001111010011100, return ...

Given a linked list, swap every two adjacent nodes and return its head.Example:Given 1-&gt;2-&gt;3-&gt;4, you should return the list as 2-&gt;1-&gt;4-&gt;3.Note:Your algorithm should use only ...

Given a binary tree, return all root-to-leaf paths.Note: A leaf is a node with no children.Example:Input:1 / \ 2 3 \ 5Output: [“1-&gt;2-&gt;5”, “1-&gt;3”]Explanation: All roo...

Write a program to find the node at which the intersection of two singly linked lists begins.For example, the following two linked lists:A: a1 → a2 ↘ ...

110： 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...

Given a non-negative integer numRows, generate the first numRows of Pascal’s triangle.In Pascal’s triangle, each number is the sum of the two numbers directly above it.Example:Input: 5 Output: ...

Given a linked list, determine if it has a cycle in it. 判断一个链表是否有环，参考了网上的方法，设计一个快指针和慢指针，让它们互相追，有点像火车相遇问题，哈哈,代码如下，这里主要容易出现空指针问题，需要注意循环条件，另外将要入职华为了，真的开始做程序员，保持初心吧，但愿coding会一直是我的乐趣，而不是变成工作的烦恼。/** ...

Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".本来这道题，我想直接用long的parseInt方法，然后发现字符串太长了超出了Long的范围，之后看了大家的答题经验之后，发现应该一位一位地处理，模仿

iven 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 without using extra

You are climbing a stair case. It takes n steps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?Note: Given n will be a positive

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree [3,9,20,null,null,15,

You are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Note:You have to rotate the image in-place, which means you have to modify the input 2D matrix d

Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.这一次用java写的，确实比用c简单了许多。。。代码入下：public class Solution { public in

203. Remove Linked List Elements Total Accepted: 89567Total Submissions: 291809Difficulty: EasyContributors: Admin Remove all elements from a linked list of integers that h

Description:Count the number of prime numbers less than a non-negative number, n.这一题用常规的判断是否是质数的方法行不通，我尝试过，最后是没有结果，这里引用一个古老的算法，下面一段复制粘贴——————————————————————我们知道2是最小的质数，那么2的倍数均不为质数（因为它们可以分解为一个

首先，这个数要非0 ，其次这个数对某个数的取余一定为为0，做如下的循环就能够判断了while（num && num%s == 0）{     num /= s;}return num==1;//这个1可能根据s的正负变化，这里默认s 为正数

374. Guess Number Higher or LowerWe are playing the Guess Game. The game is as follows:I pick a number from 1 to n. You have to guess which number I picked.Every time you guess wrong,

之前没试验过多种情况，这个应该是精简可行的/******************************************************* Author : Aaron92* Date : 2016-06-12 08:57* Filename : Binarysearch.c* Description : ******************

最近在看动态规划法，对状态转移方程总是写不出来例如今天这个问题：这个问题怎么才能抽象出状态转移方程呢？我们考虑将5个数分成3段的情形，首先考虑分成1段的时候，一个数只能分成1个段，则f[1][1] = a[1],如果是两个数呢，两个数可以分成1段则，f[2][1] = a[1] + a[2],由此易得对于i个数，f[i][1] = a[1] + a[2] + ...+a[i]。接着考虑分成

#include#include#includevoid print(int(*n)[7]);void MatrixChain(int*p,int n,int(*m)[7],int(*s)[7]);main(int argc, char** argv){ int a1[30][35],a2[35][15],a3[15][5],a4[5][10],a5[10][20],a6[20]

讨论装载问题：        有一批n个集装箱装入载重量为c的轮船，找出最多能装多少？解：一般回溯法思想，这是个子集数问题，用递归比较好写，然而不用递归怎么写呢？这里用到了迭代回溯的思想。/******************************************************* Author : Aaron92* Date : 2016-05-

网上已经有很多关于最大团的文章了，这里主要还是要用到子集树的思路，另外就是判定条件要特别注意！另外这个问题特别出名而且实用，需要多注意。/******************************************************* Author : Aaron92* Date : 2016-05-23 16:54* Filename : MaxC

问题描述：确定第一行符号，如正负号，第二行，相同符号则显示正号，不同则显示负号，a[j][i] = !(a[j-1][i]^a[j-1][i+1]),满足如下公式。理解：在用回溯法解题时，可以考虑两种思路，分别是子集树，和排列树思路。排列树在一些情况下，难以适用，如解结构不同时，而子集树，则相当于穷举，但不是简单的穷举，而是在穷举的过程中不断的裁剪废解。框架：void back

/******************************************* Name: LCSLengh* Description: Firgure out the longest same part of two* different alphabetic strings* Author: Aaron92* Time: 2016/4/* Modified

import java.awt.List;import java.util.LinkedList;import java.util.Scanner;public class Naturesort { public static void main(String[] args) { int[] a = read(); print(a); int[] b = getCo