hanfezh / leetcode

LeetCode OJ

LeetCode

How to build C++?

1. Install vcpkg

git clone https://github.com/microsoft/vcpkg
./vcpkg/bootstrap-vcpkg.sh

2. Install deps gtest

./vcpkg/vcpkg install gtest

3. Build with cmake

cmake -B build -S . "-DCMAKE_TOOLCHAIN_FILE=$(pwd)/vcpkg/scripts/buildsystems/vcpkg.cmake"
cmake --build build

Problems & Solutions

No.	Title	Difficulty	Solutions	Topics
1	Two Sum	Easy	C++ Go	Array Hash Table
2	Add Two Numbers	Medium	C++ Python	Linked List
3	Longest Substring Without Repeating Characters	Medium	C++ Python	String Sliding Window Hash Table
4	Median of Two Sorted Arrays	Hard	C++ Go	Binary Search
5	Longest Palindromic Substring	Medium	C C++	String Dynamic Programming
6	ZigZag Conversion	Medium	C	String
7	Reverse Integer	Easy	C++ Python	Math
8	String to Integer (atoi)	Medium	C++ Python	Math
9	Palindrome Number	Easy	C++ Python	Math
10	Regular Expression Matching	Hard	C++
11	Container With Most Water	Medium	C++
12	Integer to Roman	Medium	C++
13	Roman to Integer	Easy	C++	Math
14	Longest Common Prefix	Easy	C++	String
15	3Sum	Medium	C C++	Array Two Pointers Sorting
16	3Sum Closest	Medium	C++
17	Letter Combinations of a Phone Number	Medium	C++
18	4Sum	Medium	C++
19	Remove Nth Node From End of List	Medium	C++	Two Pointers
20	Valid Parentheses	Easy	C++ Python	String Stack
21	Merge Two Sorted Lists	Easy	C Python3	Linked List
22	Generate Parentheses	Medium	C++
23	Merge k Sorted Lists	Hard	C++	Sorting Priority Queue
24	Swap Nodes in Pairs	Medium	C++	Linked List
25	Reverse Nodes in k-Group	Hard	C++ Python3	Linked List Recursion
26	Remove Duplicates from Sorted Array	Easy	C++ Python	Array Two Pointers
27	Remove Element	Easy	Python	Array Two Pointers
28	Implement strStr()	Easy	C++	String KMP
29	Divide Two Integers	Medium	C++
30	Substring with Concatenation of All Words	Hard	C++	Hash Table
31	Next Permutation	Medium	C++	Array
32	Longest Valid Parentheses	Hard	C++	Stack
33	Search in Rotated Sorted Array	Medium	C++ Go	Array Binary Search
34	Find First and Last Position of Element in Sorted Array	Medium	C++
35	Search Insert Position	Easy	C++	Array Binary Search
36	Valid Sudoku	Medium	C++	Hash Table
38	Count and Say	Easy	C++	String
39	Combination Sum	Medium	C++
40	Combination Sum II	Medium	C++
41	First Missing Positive	Hard	C++	Array Hash Table
42	Trapping Rain Water	Hard	C++	Dynamic Programming
43	Multiply Strings	Medium	C++
44	Wildcard Matching	Hard	C++	Backtracking
46	Permutations	Medium	C++	DFS
47	Permutations II	Medium	C++	DFS
48	Rotate Image	Medium	C++	Array
49	Group Anagrams	Medium	C++	String
50	Pow(x, n)	Medium	C++	Binary Search
53	Maximum Subarray	Medium	C++	Array
54	Spiral Matrix	Medium	C++	Array
55	Jump Game	Medium	C++	Dynamic Programming
56	Merge Intervals	Medium	C++	Array Sorting
57	Insert Interval	Medium	C++	Array
58	Length of Last Word	Easy	C++	String
59	Spiral Matrix II	Medium	C++	Array
60	Permutation Sequence	Medium	C++
61	Rotate List	Medium	C++ Python3	Linked List
62	Unique Paths	Medium	C C++	Dynamic Programming
63	Unique Paths II	Medium	C++	Dynamic Programming
64	Minimum Path Sum	Medium	C++	Dynamic Programming
66	Plus One	Easy	C++	Array
67	Add Binary	Easy	C++	String Bit Manipulation
69	Sqrt(x)	Easy	C++	Binary search
70	Climbing Stairs	Easy	C++	Dynamic Programming
71	Simplify Path	Medium	C++
72	Edit Distance	Hard	C++	Dynamic Programming
73	Set Matrix Zeroes	Medium	C++	Array
74	Search a 2D Matrix	Medium	C++	Binary Search
75	Sort Colors	Medium	C++	Array Two Pointers
77	Combinations	Medium	C++
78	Subsets	Medium	C++
79	Word Search	Medium	C++	Backtracking
80	Remove Duplicates from Sorted Array II	Medium	C++	Array
81	Search in Rotated Sorted Array II	Medium	C++
82	Remove Duplicates from Sorted List II	Medium	C++ Python3	Linked List Two Pointers
83	Remove Duplicates from Sorted List	Easy	C++
86	Partition List	Medium	C++
88	Merge Sorted Array	Easy	C++	Two Pointers
89	Gray Code	Medium	C++	Bit Manipulation
90	Subsets II	Medium	C++
91	Decode Ways	Medium	C++	Dynamic Programming
92	Reverse Linked List II	Medium	C++	Linked List
93	Restore IP Addresses	Medium	C++	DFS
94	Binary Tree Inorder Traversal	Medium	C++ Go	Tree Stack
95	Unique Binary Search Trees II	Medium	C++	Tree
96	Unique Binary Search Trees	Medium	C++	Dynamic Programming
98	Validate Binary Search Tree	Medium	C++	DFS Inorder Traversal
99	Recover Binary Search Tree	Medium	C++	DFS Inorder Traversal
100	Same Tree	Easy	C++	Tree DFS BFS
101	Symmtric Tree	Easy	C++	Tree DFS BFS
102	Binary Tree Level Order Traversal	Medium	C++	Tree BFS DFS
103	Binary Tree Zigzag Level Order Traversal	Medium	C++	Tree
104	Maximum Depth of Binary Tree	Easy	C++	Tree DFS
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	C++	Tree DFS
106	Construct Binary Tree from Inorder and Postorder Traversal	Medium	C++	Tree DFS
107	Binary Tree Level Order Traversal II	Easy	C++	Tree
108	Convert Sorted Array to Binary Search Tree	Easy	C++	Tree
109	Convert Sorted List to Binary Search Tree	Medium	C++	Tree
110	Balanced Binary Tree	Easy	C++	Tree DFS
111	Minimum Depth of Binary Tree	Easy	C++	Tree
112	Path Sum	Easy	C++ Python	Tree DFS
113	Path Sum II	Medium	Python
114	Flatten Binary Tree to Linked List	Medium	C++	Tree
115	Distinct Subsequences	Hard	C++	Dynamic Programming
116	Populating Next Right Pointers in Each Node	Medium	C++	Tree DFS
117	Populating Next Right Pointers in Each Node II	Medium	C++	Tree BFS DFS
118	Pascal's Triangle	Easy	C++	Array
119	Pascal's Triangle II	Easy	C++	Array
120	Triangle	Medium	C++	Dynamic Programming
121	Best Time to Buy and Sell Stock	Easy	C++	Array
122	Best Time to Buy and Sell Stock II	Easy	C++	Array
123	Best Time to Buy and Sell Stock III	Hard	C++
124	Binary Tree Maximum Path Sum	Hard	C++	Tree DFS
125	Valid Palindrome	Easy	C++	String Two Pointers
126	Word Ladder II	Hard	C++	BFS
127	Word Ladder	Medium	C++	BFS
128	Longest Consecutive Sequence	Medium	C++	Array
129	Sum Root to Leaf Numbers	Medium	C++	DFS
130	Surrounded Regions	Medium	C++	Union Find
131	Palindrome Partitioning	Medium	C++	DFS
133	Clone Graph	Medium	C++ Python3	Hash Table DFS BFS
136	Single Number	Easy	Python	Bit Manipulation
137	Single Number II	Medium	C++	Bit Manipulation
138	Copy List with Random Pointer	Medium	C++	Linked List
139	Word Break	Medium	C++	Dynamic Programming
140	Word Break II	Hard	C++	DFS Dynamic Programming
141	Linked List Cycle	Easy	C++	Linked List Two Pointers
142	Linked List Cycle II	Medium	C++	Hash Table Two Pointers
143	Reorder List	Medium	C C++	Recursion
144	Binary Tree Preorder Traversal	Medium	C++	Tree Stack
145	Binary Tree Postorder Traversal	Hard	C++	Tree Stack
146	LRU Cache	Medium	C++	Design
147	Insertion Sort List	Medium	C
148	Sort List	Medium	C++ Python3	Sorting Merge Sort
149	Max Points on a Line	Hard	C++	Math
150	Evaluate Reverse Polish Notation	Medium	C++	Stack
151	Reverse Words in a String	Medium	C++
152	Maximum Product Subarray	Medium	C++	Dynamic Programming
153	Find Minimum in Rotated Sorted Array	Medium	C C++	Binary Search
154	Find Minimum in Rotated Sorted Array II	Hard	C C++	Binary Search
155	Min Stack	Easy	C++ Python	Stack Design
160	Intersection of Two Linked Lists	Easy	C++	Two Pointers
162	Find Peak Element	Medium	C++	Binary Search
163	Missing Ranges	Easy	C++	Array
164	Maximum Gap	Hard	C++	Sorting Bucket Sort
165	Compare Version Numbers	Medium	C++ Python3	String
167	Two Sum II - Input array is sorted	Easy	C++
168	Excel Sheet Column Title	Easy	C++	Math
169	Majority Element	Easy	C++	Array Sorting Hash Table
171	Excel Sheet Column Number	Easy	C++	Math String
173	Binary Search Tree Iterator	Medium	C++	Tree Stack
175	Combine Two Tables	Easy	MySQL	Database
176	Second Highest Salary	Easy	MySQL	Database
177	Nth Highest Salary	Medium	MySQL	Database
178	Rank Scores	Medium	MySQL	Database
179	Largest Number	Medium	Python
189	Rotate Array	Easy	C	Array
197	Rising Temperature	Easy	MySQL
190	Reverse Bits	Easy	C++	Bit Manipulation
191	Number of 1 Bits	Easy	C++	Bit Manipulation
192	Word Frequency	Medium	Bash
193	Valid Phone Numbers	Easy	Bash
194	Transpose File	Medium	Bash
195	Tenth Line	Easy	Bash
196	Delete Duplicate Emails	Easy	MySQL
198	House Robber	Easy	C++	Dynamic Programming
199	Binary Tree Right Side View	Medium	C++	BFS
200	Number of Islands	Medium	C++	Union Find
202	Happy Number	Easy	C++ Go Python3	Hash Table Two Pointers
203	Remove Linked List Elements	Easy	C++	Linked List
204	Count Primes	Easy	C++	Math
205	Isomorphic Strings	Easy	Go	Hash Table
206	Reverse Linked List	Easy	C++ Python3	Linked List Recursion
208	Implement Trie (Prefix Tree)	Medium	C++	Design Trie
209	Course Schedule	Medium	C++	DFS Graph
215	Kth Largest Element in an Array	Medium	C++	Sorting Priority Queue
216	Combination Sum III	Medium	C++
217	Contains Duplicate	Easy	C++	Hash Table Sorting
219	Contains Duplicate II	Easy	C++
220	Contains Duplicate III	Medium	C++
222	Count Complete Tree Nodes	Medium	C++	Tree DFS
224	Basic Calculator	Hard	C++	String Stack
225	Implement Stack using Queues	Easy	C++	Stack Queue
226	Invert Binary Tree	Easy	C++	Tree DFS
227	Basic Calculator II	Medium	C++	String Stack
228	Summary Ranges	Easy	Python3	Array
230	Kth Smallest Element in a BST	Medium	C++	Tree BFS
232	Implement Queue using Stacks	Easy	C++	Stack Queue
234	Palindrome Linked List	Medium	C++	Linked List Two Pointers
235	Lowest Common Ancestor of a Binary Search Tree	Easy	C++	Tree DFS
236	Lowest Common Ancestor of a Binary Tree	Medium	C++ Go	Tree DFS
237	Delete Node in a Linked List	Easy	C++	Linked List
238	Product of Array Except Self	Medium	C++	Array Prefix Sum
242	Valid Anagram	Easy	C++	String Hash Table
257	Binary Tree Paths	Easy	C++
258	Add Digits	Easy	Python3	Math
263	Ugly Number	Easy	Python
268	Missing Number	Easy	C++	Array Math
274	H-Index	Medium	C++	Sorting
278	First Bad Version	Easy	C++	Binary Search
283	Move Zeroes	Easy	C++	Two Pointers
286	Walls and Gates	Medium	C++	Matrix DFS
287	Find the Duplicate Number	Medium	C++	Two Pointers
292	Nim Game	Easy	C++	Brainteaser
295	Find Median from Data Stream	Hard	C++	Sorting Priority Queue
297	Serialize and Deserialize Binary Tree	Hard	C++	Tree DFS
300	Longest Increasing Subsequence	Medium	C++	Dynamic Programming
303	Range Sum Query - Immutable	Easy	C++	Array
322	Coin Change	Medium	C++	Dynamic Programming
326	Power of Three	Easy	C++	Math
328	Odd Even Linked List	Medium	C++	Linked List
334	Increasing Triplet Subsequence	Medium	C++
338	Counting Bits	Easy	C++	Dynamic Programming
344	Reverse String	Easy	C++	Two Pointers
347	Top K Frequent Elements	Medium	C++	Hash Table Heap
348	Design Tic-Tac-Toe	Medium	C++	Matrix
349	Intersection of Two Arrays	Easy	C++	Hash Table
350	Intersection of Two Arrays II	Easy	C++	Hash Table
367	Valid Perfect Square	Easy	C++	Binary Search
371	Sum of Two Integers	Easy	C++
374	Guess Number Higher or Lower	Easy	C++	Binary Search
377	Combination Sum IV	Medium	C++
382	Linked List Random Node	Medium	C++	Linked List
383	Ransom Note	Easy	C++ Python3	Hash Table
384	Shuffle an Array	Medium	C++	Design
386	Lexicographical Numbers	Medium	C++
387	First Unique Character in a String	Easy	C++	Hash Table
389	Find the Difference	Easy	C++	Hash Table Bit Manipulation
392	Is Subsequence	Easy	C++ Python3	String
397	Integer Replacement	Medium	C++
404	Sum of Left Leaves	Easy	C++	Tree
409	Longest Palindrome	Easy	C++	String Hash Table
410	Split Array Largest Sum	Hard	C++	Binary Search
412	Fizz Fuzz	Easy	C++	Math
414	Third Maximum Number	Easy	C++	Sorting
415	Add Strings	Easy	C++
429	N-ary Tree Level Order Traversal	Medium	C++	Tree BFS
430	Flatten a Multilevel Doubly Linked List	Medium	C++	Linked List
437	Path Sum III	Easy	C++
442	Find All Duplicates in an Array	Medium	C++
443	String Compression	Easy	C++
448	Find All Numbers Disappeared in an Array	Easy	C++
451	Sort Characters By Frequency	Medium	C++ Python3	Hash Table Sorting
452	Minimum Number of Arrows to Burst Balloons	Medium	C++ Python3	Sorting
455	Assign Cookies	Easy	C++	Sorting Two Pointers
461	Hamming Distance	Easy	C++	Bit Manipulation
477	Total Hamming Distance	Medium	C++	Math Bit Manipulation
480	Sliding Window Median	Hard	C++	Array
485	Max Consecutive Ones	Easy	C++	Array
487	Max Consecutive Ones II	Medium	C++	Array Two Pointers
491	Increasing Subsequences	Medium	C++
501	Find Mode in Binary Search Tree	Easy	C++
509	Fibonacci Number	Easy	C++	Array Dynamic Programming
523	Continuous Subarray Sum	Medium	C++
524	Longest Word in Dictionary through Deleting	Medium	C++	Sorting Two Pointers
540	Single Element in a Sorted Array	Medium	C++	Bit Manipulation Binary Search
541	Reverse String II	Easy	C++
542	01 Matrix	Medium	C++	BFS Dynamic Programming
543	Diameter of Binary Tree	Easy	C++	Tree DFS
560	Subarray Sum Equals K	Medium	C++	Array
563	Binary Tree Tilt	Easy	C++	Tree DFS
594	Longest Harmonious Subsequence	Easy	C++	Hash Table
599	Minimum Index Sum of Two Lists	Easy	C++
623	Add One Row to Tree	Medium	C++
628	Maximum Product of Three Numbers	Easy	Go
629	K Inverse Pairs Array	Hard	C++	Dynamic Programming
645	Set Mismatch	Easy	C++
653	Two Sum IV - Input is a BST	Easy	C++
658	Find K Closest Elements	Medium	C++	Binary Search
662	Maximum Width of Binary Tree	Medium	C++	Binary Tree BFS
670	Maximum Swap	Medium	C++	Math
680	Valid Palindrome II	Easy	C++	String Two Pointers
704	Binary Search	Easy	C++	Array Binary Search
705	Design HashSet	Easy	C++	Bit Manipulation Hash Table
706	Design HashMap	Easy	C++	Array Hash Table
707	Design Linked List	Medium	C++	Linked List
716	Max Stack	Hard	C++	Ordered Set Priority Queue
719	Find K-th Smallest Pair Distance	Hard	C++	Binary Search
733	Flood Fill	Easy	C++	Array DFS
739	Daily Temperatures	Medium	C++	Stack
744	Find Smallest Letter Greater Than Target	Easy	C++	Binary Search
765	Couples Holding Hands	Hard	C++	Union Find
772	772. Basic Calculator III	Hard	C++	String Stack
779	K-th Symbol in Grammar	Medium	C++	Recursion
788	Rotated Digits	Easy	C++	Dynamic Programming
796	Rotate String	Easy	C++	String
799	Champagne Tower	Medium	C++	Dynamic Programming
867	Transpose Matrix	Easy	C++	Matrix
876	Middle of the Linked List	Easy	C++	Linked List Two Pointers
899	Orderly Queue	Hard	C++	Math String
905	Sort Array By Parity	Easy	C++	Array Two Pointers
912	Sort an Array	Medium	C++	Array Merge Sort Heap Sort
921	Minimum Add to Make Parentheses Valid	Medium	C++	String Stack
922	Sort Array By Parity II	Easy	C++	Array Two Pointers
965	Univalued Binary Tree	Easy	C++	BFS
973	K Closest Points to Origin	Medium	C++	Array Sorting Priority Queue
977	Squares of a Sorted Array	Easy	C++	Array Two Pointers
989	Add to Array-Form of Integer	Easy	C++	Array Math
993	Cousins in Binary Tree	Easy	C++	Tree DFS
997	Find the Town Judge	Easy	C++	Graph
1004	Max Consecutive Ones III	Medium	C++	Array Two Pointers
1051	Height Checker	Easy	C++	Array Sorting Counting Sort
1093	Statistics from a Large Sample	Medium	C++	Array Math
1134	Armstrong Numberhttps://leetcode.com/problems/armstrong-number/	Easy	C++	Math
1206	Design Skiplist	Hard	C++	Linked List
1207	Unique Number of Occurrences	Easy	C++	Hash Table
1247	Minimum Swaps to Make Strings Equal	Medium	C++	Math String
1288	Remove Covered Intervals	Medium	C++	Array Sorting
1365	How Many Numbers Are Smaller Than the Current Numberhttps://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number/	Easy	C++	Sorting Hash Table
1366	Rank Teams by Votes	Medium	C++	Array Sorting
1381	Design a Stack With Increment Operation	Medium	C++	Array Stack
1382	Balance a Binary Search Tree	Medium	C++	Binary Search Tree
1539	Kth Missing Positive Number	Easy	C++	Array Hash Table
1641	Count Sorted Vowel Strings	Medium	C++	Dynamic Programming
1679	Max Number of K-Sum Pairs	Medium	C++	Hash Table
1720	Decode XORed Array	Easy	C++	Bit Manipulation
2032	Two Out of Three	Easy	C++	Set Map
2092	Find All People With Secret	Hard	C++	Union Find
2108	Find First Palindromic String in the Array	Easy	C++	Two Pointers
2177	Find Three Consecutive Integers That Sum to a Given Number	Medium	C++	Math
2293	Min Max Game	Easy	C++	Array
2864	Maximum Odd Binary Number	Easy	C++	Math String
2951	Find the Peaks	Easy	C++	Array