gq97-CSDN博客

原创 LeetCode 50. Pow(x, n)

LeetCode 50. Pow(x, nDescriptionExampleNoteCodeConclusionDescriptionImplement pow(x, n), which calculates x raised to the power n (xn).ExampleNote-100.0 < x < 100.0n is a 32-bit signed i...

2019-06-25 18:45:28 259

原创 LeetCode 47. Permutations II

LeetCode 47. Permutations IIDescriptionExampleCodeConclusionDescriptionGiven a collection of numbers that might contain duplicates, return all possible unique permutations.ExampleCodejavaclas...

2019-06-24 22:39:04 244

原创 LeetCode 41. First Missing Positive

LeetCode 41. First Missing PositiveDescriptionNoteExampleCodeConclusionDescriptionGiven an unsorted integer array, find the smallest missing positive integer.NoteYour algorithm should run in O(n) ...

2019-06-18 11:27:30 251

原创 LeetCode 40. Combination Sum II

LeetCode 40. Combination Sum IIDescriptionNoteExampleCodeConclusionDescriptionGiven a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candi...

2019-06-18 11:06:57 173

原创 LeetCode 39. Combination Sum

LeetCode 39. Combination SumDescriptionNoteExampleCodeConclusionDescriptionGiven a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinatio...

2019-06-18 10:46:09 128

原创 LeetCode 30. Substring with Concatenation of All Words

LeetCode 30. Substring with Concatenation of All WordsDescriptionExampleCodeConclusionDescriptionYou are given a string, s, and a list of words, words, that are all of the same length. Find all star...

2019-06-06 17:00:38 159

原创 LeetCode 29. Divide Two Integers

LeetCode 29. Divide Two IntegersDescriptionExampleNoteCodeConclusionDescriptionGiven two integers dividend and divisor, divide two integers without using multiplication, division and mod operator.R...

2019-05-29 21:52:59 244

原创 LeetCode 28. Implement strStr

LeetCode 28. Implement strStrDescriptionExampleClarificationCodeConclusionDescriptionImplement strStr().Return the index of the first occurrence of needle in haystack, or -1 if needle is not part o...

2019-05-29 21:43:17 261

原创 LeetCode 27. Remove Element

LeetCode 27. Remove ElementDescriptionExampleClarificationCodeConclusionDescriptionGiven an array nums and a value val, remove all instances of that value in-place and return the new length.Do not ...

2019-05-27 21:37:11 113

原创 LeetCode 26. Remove Duplicates from Sorted Array

LeetCode 26. Remove Duplicates from Sorted ArrayDescriptionExampleClarificationCodeConclusionDescriptionGiven a sorted array nums, remove the duplicates in-place such that each element appear only o...

2019-05-26 22:43:37 116

原创 LeetCode 25. Reverse Nodes in k-Group

LeetCode 25. Reverse Nodes in k-GroupDescriptionExampleNoteCodeConclusionDescriptionGiven a linked list, reverse the nodes of a linked list k at a time and return its modified list.k is a positive ...

2019-05-26 22:31:13 189

原创 LeetCode 24. Swap Nodes in Pairs

LeetCode 24. Swap Nodes in PairsDescriptionExampleCodeConclusionDescriptionGiven a linked list, swap every two adjacent nodes and return its head.You may not modify the values in the list’s nodes, ...

2019-05-26 22:09:36 173

原创 LeetCode 23. Merge k Sorted Lists

LeetCode 23. Merge k Sorted ListsDescriptionExampleCodeConclusionDescriptionMerge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.ExampleInput:[ 1-&g...

2019-05-23 22:12:49 127

原创 LeetCode 22. Generate Parentheses

LeetCode 22. Generate ParenthesesDescriptionExampleCodeConclusionDescriptionGiven n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.ExampleFor exampl...

2019-05-23 22:03:05 116

原创 LeetCode 21. Merge Two Sorted Lists

LeetCode 21. Merge Two Sorted ListsDescriptionExampleCodeConclusionDescriptionMerge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of...

2019-05-21 21:54:45 108

原创 LeetCode 20. Valid Parentheses

LeetCode 20. Valid ParenthesesDescriptionExampleCodeConclusionDescriptionGiven a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.An inp...

2019-05-21 11:18:39 107

原创 LeetCode 19. Remove Nth Node From End of List

LeetCode 19. Remove Nth Node From End of ListDescriptionExampleNoteCodeConclusionDescriptionGiven a linked list, remove the n-th node from the end of list and return its head.ExampleNoteGiven n ...

2019-05-20 00:01:59 153

原创 LeetCode 18. 4Sum

LeetCode 18. 4SumDescriptionExampleNoteCodeConclusionDescriptionGiven an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? F...

2019-05-19 23:57:00 181

原创 LeetCode 17. Letter Combinations of a Phone Number

LeetCode 17. Letter Combinations of a Phone NumberDescriptionExampleNoteCodeConclusionDescriptionGiven a string containing digits from 2-9 inclusive, return all possible letter combinations that the...

2019-05-17 21:28:06 200

原创 LeetCode 16. 3Sum Closest

LeetCode 16. 3Sum ClosestDescriptionExampleCodeConclusionDescriptionGiven an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Retur...

2019-05-17 09:56:05 112

原创 LeetCode 15. 3Sum

LeetCode 15. 3SumDescriptionExampleCodeConclusionDescriptionGiven an array numsof n integers, are there elements a, b, c in numssuch that a + b + c = 0? Find all unique triplets in the array which g...

2019-05-16 09:30:19 128

原创 LeetCode 14. Longest Common Prefix

LeetCode 14. Longest Common PrefixDescriptionExampleNoteCodeConclusionDescriptionWrite a function to find the longest common prefix string amongst an array of strings.If there is no common prefix, ...

2019-05-14 21:37:22 154

原创 LeetCode 13. Roman to Integer

LeetCode 13. Roman to IntegerDescriptionExampleCodeConclusionDescriptionRoman numerals are represented by seven different symbols: I, V, X, L, C, D and M.Symbol ValueI 1V ...

2019-04-28 00:03:48 91

原创 LeetCode 12. Integer to Roman

LeetCode 12. Integer to RomanDescriptionExampleCodeConclusionDescriptionRoman numerals are represented by seven different symbols: I, V, X, L, C, D and M.Symbol ValueI 1V ...

2019-04-26 22:48:36 103

原创 LeetCode 11. Container With Most Water

LeetCode 11. Container With Most WaterDescriptionExampleCodeConclusionDescriptionGiven n non-negative integers a1, a2, …, an , where each represents a point at coordinate (i, ai). n vertical lines a...

2019-04-25 22:13:05 147

原创 LeetCode 10. Regular Expression Matching

LeetCode 10. Regular Expression MatchingDescriptionNoteExampleCodeConclusionDescriptionGiven an input string (s) and a pattern (p), implement regular expression matching with support for'.'and'*'....

2019-04-23 22:32:11 142

原创 LeetCode 9. Palindrome Number

LeetCode 9. Palindrome NumberDescriptionExampleFollow upCodeConclusionDescriptionDetermine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward....

2019-04-22 21:58:44 199

原创 LeetCode 8. String to Integer (atoi)

LeetCode 8. String to Integer (atoiDescriptionNoteExampleCodeConclusionDescriptionImplement atoi which converts a string to an integer.The function first discards as many whitespace characters as n...

2019-04-21 23:16:17 116

原创 LeetCode 7. Reverse Integer

LeetCode 7. Reverse IntegerDescriptionExampleCodeConclusionDescriptionGiven a 32-bit signed integer, reverse digits of an integer.ExampleCodejavaclass Solution { public int reverse(int x)...

2019-04-20 21:19:11 259

原创 LeetCode 6. ZigZag Conversion

LeetCode 6. ZigZag ConversionDescriptionExampleCodeConclusionDescriptionExampleCodejavaclass Solution { public String convert(String s, int numRows) { if(numRows < 2 || s == nu...

2019-04-16 23:09:13 97

原创 LeetCode 4. Median of Two Sorted Arrays

LeetCode 4. Median of Two Sorted ArraysDescriptionExampleCodeConclusionDescriptionThere are two sorted arrays nums1 and nums2 of size m and n respectively.Find the median of the two sorted arrays. ...

2019-04-02 15:14:06 134

原创 LeetCode 3. Longest Substring Without Repeating Characters

LeetCode 3. Longest Substring Without Repeating CharactersDescriptionExampleCodeConclusionDescriptionGiven a string, find the length of the longest substring without repeating characters.ExampleC...

2019-04-02 11:39:23 140

原创 LeetCode 2. Add Two Numbers

LeetCode 2. Add Two NumbersDescriptionExampleCodeConclusionDescriptionYou are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each...

2019-03-31 17:25:18 159

原创剑指offer之矩形覆盖

剑指offer之矩形覆盖题目描述解题思路Code总结题目描述我们可以用2*1的小矩形横着或者竖着去覆盖更大的矩形。请问用n个2*1的小矩形无重叠地覆盖一个2*n的大矩形，总共有多少种方法？解题思路其实动手推一下就会发现是一个Fibonacci数列f(0) = 0;f(1) = 1;f(2) = 2;…f(n) = f(n-1)+f(n-2);Codecppclass S...

2019-03-09 16:55:04 77

原创 PAT Advanced 1032 Sharing （25 ）

PAT Advanced 1032 Sharing （25 ）题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述Input Specification:Output Specification:Sample Input:11111 22222 967890 i 0...

2019-03-01 17:50:14 155

原创 PAT Advanced 1143 Lowest Common Ancestor （30 ）

PAT Advanced 1143 Lowest Common Ancestor （30 ）题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述The lowest common ancestor (LCA) of two nodes U and V in a tree is t...

2019-03-01 17:39:12 96

原创 PAT Advanced 1155 Heap Paths （30 ）

PAT Advanced 1155 Heap Paths （30 ）题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述In computer science, a heap is a specialized tree-based data structure that sati...

2019-03-01 17:17:32 113

原创 PAT Advanced 1154 Vertex Coloring （25 ）

PAT Advanced 1154 Vertex Coloring （25 ）题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述A proper vertex coloring is a labeling of the graph’s vertices with colors ...

2019-03-01 17:07:25 135

原创层序和中序重建二叉树

层序和中序重建二叉树题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述输入一棵二叉树的层序和中序遍历，分别输出其前序和后序遍历Input Specification:第一行输入树的大小，接下来一行给出树的层序遍历，最后一行给出树的中序遍历。Output Specifica...

2019-03-01 12:19:49 1264

原创 PAT Advanced 1072 Gas Station （30 ）

PAT Advanced 1072 Gas Station （30 ）题目描述Input Specification:Output Specification:Sample Input:Sample Output:解题思路Code题目描述A gas station has to be built at such a location that the minimum distance betw...

2019-02-28 22:14:03 104

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