Garvin的专栏

1.题目There are N children standing in a line. Each child is assigned a rating value.You are giving candies to these children subjected to the following requirements:Each child must have at least one ca

题目Given a 2D binary matrix filled with 0's and 1's, find the largest square containing all 1's and return its area.For example, given the following matrix:1 0 1 0 01 0 1 1 11 1 1 1 11 0 0 1 0Retur

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:"((()))", "(()())", "(())()", "()(())", "()()()"代码F

背景（以下背景资料转载自：http://www.cnblogs.com/springfor/p/3874591.html?utm_source=tuicool）DFS（Dpeth-first Search）顾名思义，就是深度搜索，一条路走到黑，再选新的路。记得上Algorithm的时候，教授举得例子就是说，DFS很像好奇的小孩，你给这个小孩几个盒子套盒子，好奇的小孩肯定会一个盒子打开后继续再在这个

1.时间复杂度O(N),内存O(1)的效率下实现单链表的翻转public static TreeNode revers(TreeNode head){ TreeNode temp,first,second; first=head; second=head.next; while(second!=null){ temp=second.next; second.next=

题目Say you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), d

题目Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).For example, the 32-bit integer ’11' has binary representation 0000000000

题目Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. Fo

题目Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened tree should look like: 1 \ 2

题目Given numRows, generate the first numRows of Pascal's triangle.For example, given numRows = 5,Return[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1]]代码public class Solution { public

题目Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.For example:Given the below binary tree and sum =

题目Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.代码/** * Definition for binary tree * p

题目       Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 /

题目1.same treeGiven 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 same value.2.sym

题目Given a sorted linked list, delete all duplicates such that each element appear only once.For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3, return 1->2->3.代码 public static ListNode deleteD

题目Given two sorted integer arrays A and B, merge B into A as one sorted array.Note:You may assume that A has enough space (size that is greater or equal to m + n) to hold additional elements from B. T

题目          爬楼梯问题，这是一道很有趣的问题。首先看题目：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?这

题目Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".代码public class Solution { public String addBinary(String a, String b) { S

题目The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ...1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one 2, then

题目Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is defined

题目      判断数独是否成立的一道题，看的是某大神的答案，写的太漂亮了。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 charact

题目    Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't matter what you leave beyond the new length.代码p

题目Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.代码public class Solution { public int strStr(String haystack, String ne

题目      这道题是链表的简单应用，将两个有序链表合成一个有序链表。       思路是：表一，表二各取两个对象，分别指向current和next，进行交叉比较排序。Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nod

题目       题目很简单，就是写一个函数把string转换成int，但是通过率只有可怜的11%，难点是要考虑所有情况，特别是int溢出边界，反正我是写了2个小时还没解决，先放到这，有空接着搞，现在应该还有最后一个bug。Implement atoi to convert a string to an integer.Hint: Carefully consider all possible i

题目     题目要求：去除sort int数组中的重复项。     Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.Do not allocate extra space for another array,

题目        这是道链表的简单应用题目，删除从结尾数第n个节点。Given a linked list, remove the nth node from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the

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

题目    Write a function to find the longest common prefix string amongst an array of strings.代码public class Solution { public String longestCommonPrefix(String[] strs) { if(strs.length==0)

题目      这道题是迄今为止最快通过的一道题，改了两次就过了，runtime一般（中等偏下，这点不太满意）。Palindrome就是判断一个整数是否对称。Determine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negativ

前话      今天开始励志刷一下leetcode上面的题目（还好这个网站没被TG和谐）。从easy的开始，数一下差不多有40道，争取两个月搞定。题目       没想到做的第一道题目，虽然看似简单，却费了很大周折。题目如下：Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -3