ywheel的专栏

package ywheel.leetcode._003_longest_substring_without_repeating_characters;/** * Given a string, find the length of the longest substring without repeating * characters. For example, the longest

转载自豆瓣： http://www.douban.com/note/330562764/，的确需要有一个分类列表在指导自己在准备时间不够充分的情况下接触到更多考点的题欢迎参考我的leetcode代码利用堆栈：http://oj.leetcode.com/problems/evaluate-reverse-polish-notation/http://oj.leetcod

题：https://leetcode.com/problems/merge-k-sorted-lists/Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.解法一：将K个链表做K-1次归并，每次归并是对两个链表的归并，最终得到一个

题：https://leetcode.com/problems/merge-sorted-array/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

题目：https://leetcode.com/problems/plus-one/Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit

题：https://leetcode.com/problems/merge-two-sorted-lists/Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two li

转载自：http://blog.youkuaiyun.com/feliciafay/article/details/18944093Topic 1 反转链表Reverse Linked List II在第m~n个节点中反转单链表，注意这道题可以把代码写得很长，如果分为区间一[0,m-1],区间二[m-n],区间三[n+1,end]这三个区间的话。也可以写得很短，如果仔细观察发现

题目：https://leetcode.com/problems/search-in-rotated-sorted-array/Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1

题目：https://leetcode.com/problems/search-for-a-range/Given a sorted array of integers, find the starting and ending position of a given target value.Your algorithm's runtime complexity must

题目：https://leetcode.com/problems/search-insert-position/Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were

public class Solution { public void sortColors(int[] A) { if (A == null || A.length == 0) return; int zero = 0; int two = A.length - 1; int i = 0; whil

题目大意是给定一个只有左右括号组成的字符串，求最长的valid字串长度，比如“()”的最长valid字串长度为2，“)()())”的最长valid字串为"()()"，则长度为4.拿到这个题目第一反应就是用Stack，但是Stack里面装什么呢？如何表示Valid最大长度？后来想到是否能够把还没匹配好的括号的index放到stack中，如果有匹配的就pop，没有就push。当pop的时候

题：https://leetcode.com/problems/pascals-triangle-ii/Given an index k, return the kth row of the Pascal's triangle.For example, given k = 3,Return [1,3,3,1].Note:Could you optimiz

连续两次随机到关于括号的题了，跟括号真有缘。。。好了，别的不多说，上代码：package ywheel.leetcode._22_generate_parentheses;import java.util.ArrayList;import java.util.List;/** * Given n pairs of parentheses, write a function to

/** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */public class Solution { publi

package ywheel.leetcode._001_two_sum;import java.util.Arrays;import java.util.Comparator;/** * Given an array of integers, find two numbers such that they add up to a * specific target number.

package ywheel.leetcode._002_add_two_numbers;/** * You are given two linked lists representing two non-negative numbers. The * digits are stored in reverse order and each of their nodes contain a

题：https://leetcode.com/problems/insertion-sort-list/Sort a linked list using insertion sort./** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode