AkibaTakuya-优快云博客

原创 leetcode - Min Stack

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top() -- Get

2014-11-19 13:10:45 974

原创 leetcode - Find Minimum in Rotated Sorted Array II

Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed?Would this affect the run-time complexity? How and why?Suppose a sorted array is rotated at some pivot unk

2014-10-26 19:49:25 625

原创 leetcode - Find Minimum 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 2).Find the minimum element.You may assume no duplicate exists in

2014-10-26 19:29:48 630

原创 leetcode - Maximum Product Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest product.For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest

2014-10-26 18:59:55 561

原创 leetcode - Word Search

Given a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically

2014-10-26 18:19:01 555

原创 leetcode - Surrounded Regions

Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'.A region is captured by flipping all 'O's into 'X's in that surrounded region.For example,X X X XX O O X

2014-10-26 18:07:46 447

原创 leetcode - Word Ladder II

Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that:Only one letter can be changed at a timeEach intermediate word must exi

2014-10-26 17:45:35 572

原创 leetcode - Word Ladder

Given two words (start and end), and a dictionary, find the length of shortest transformation sequence from start to end, such that:Only one letter can be changed at a timeEach intermediate word m

2014-10-26 17:09:57 995

原创 leetcode - Minimum Window Substring

Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n).For example,S = "ADOBECODEBANC"T = "ABC"Minimum window is "BAN

2014-10-26 16:56:02 699

原创 leetcode - Decode Ways

A message containing letters from A-Z is being encoded to numbers using the following mapping:'A' -> 1'B' -> 2...'Z' -> 26Given an encoded message containing digits, determine the total numb

2014-10-26 15:56:10 578

原创 leetcode - Simplify Path

Given an absolute path for a file (Unix-style), simplify it.For example,path = "/home/", => "/home"path = "/a/./b/../../c/", => "/c"click to show corner cases.Corner Cases:Did

2014-10-26 15:45:45 592

原创 leetcode - Text Justification

Given an array of words and a length L, format the text such that each line has exactly L characters and is fully (left and right) justified.You should pack your words in a greedy approach; that i

2014-10-26 15:32:02 674

原创 leetcode - Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially sorted according to their start times.E

2014-10-26 15:14:50 604

原创 leetcode - Merge Intervals

Given a collection of intervals, merge all overlapping intervals.For example,Given [1,3],[2,6],[8,10],[15,18],return [1,6],[8,10],[15,18].bool operator < (const Interval &a, const Interval

2014-10-26 14:37:11 566

原创 leetcode - N-Queens II

Follow up for N-Queens problem.Now, instead outputting board configurations, return the total number of distinct solutions.class Solution {private: int res;public: int totalNQuee

2014-10-26 14:11:32 557

原创 leetcode - N-Queens

The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.Given an integer n, return all distinct solutions to the n-queens puzzle.

2014-10-26 13:40:12 775

原创 leetcode - Jump Game II

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Your goal i

2014-10-26 13:08:38 754

原创 leetcode - Wildcard Matching

Implement wildcard pattern matching with support for '?' and '*'.'?' Matches any single character.'*' Matches any sequence of characters (including the empty sequence).The matching should cover t

2014-10-26 12:56:44 574

原创 leetcode - Trapping Rain Water

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.For example, Given [0,1,0,2,1,0,1,3,2,1,2,1]

2014-10-26 12:50:08 556

原创 leetcode - First Missing Positive

Given an unsorted integer array, find the first missing positive integer.For example,Given [1,2,0] return 3,and [3,4,-1,1] return 2.Your algorithm should run in O(n) time and uses constant

2014-10-26 12:45:07 552

原创 leetcode - 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 2).You are given a target value to search. If found in the array retur

2014-10-26 11:09:49 637

原创 leetcode - Longest Valid Parentheses

Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.For "(()", the longest valid parentheses substring is "()",

2014-10-26 10:31:26 497

原创 leetcode - Substring with Concatenation of All Words

You are given a string, S, and a list of words, L, that are all of the same length. Find all starting indices of substring(s) in S that is a concatenation of each word in L exactly once and without

2014-10-25 20:38:29 509

原创 leetcode - Longest Substring Without Repeating Characters

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

2014-10-25 20:20:25 511

原创 leetcode - Median of Two Sorted Arrays

There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).class Solution {public: int

2014-10-25 19:51:14 470

原创 leetcode - ZigZag Conversion

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H NA P L S I

2014-10-25 19:43:14 430

原创 leetcode - Regular Expression Matching

Implement regular expression matching with support for '.' and '*'.'.' Matches any single character.'*' Matches zero or more of the preceding element.The matching should cover the entire input st

2014-10-25 19:33:26 432

原创 leetcode - Container With Most Water

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 line i is at (i, ai) and (i, 0). Fin

2014-10-25 19:28:45 444

原创 leetcode - 4Sum

Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note:Element

2014-10-25 19:19:52 348

原创 leetcode - Letter Combinations of a Phone Number

Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is given below.Input:Digit st

2014-10-25 19:14:01 554

原创 leetcode - Valid Parentheses

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 va

2014-10-25 18:59:45 374

原创 leetcode - Generate Parentheses

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:"((()))", "(()())", "(())()", "()(())", "()()

2014-10-25 18:21:51 386

原创 leetcode - Merge k Sorted Lists

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity./** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *ne

2014-10-25 18:06:45 381

原创 leetcode - Reverse Nodes in k-Group

Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end should remain as it is

2014-10-25 17:38:02 484

原创 leetcode - Remove Duplicates from Sorted Array

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, you must do this in place with

2014-10-25 17:17:42 550

原创 leetcode - Implement strStr()

Implement strStr().Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack.class Solution {public: char *strStr(char *haystack, char *ne

2014-10-25 16:57:25 557

原创 leetcode - 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 be in the order of O(log n).If the target is not found

2014-10-25 16:49:30 554

原创 leetcode - 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 inserted in order.You may assume no duplicates in the array.

2014-10-25 16:16:47 507

原创 leetcode - Valid Sudoku

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 character '.'.A partially fille

2014-10-25 15:50:24 1399

原创 leetcode - Sudoku Solver

Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character '.'.You may assume that there will be only one unique solution.A sudoku

2014-10-25 15:36:01 1707

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