LeetCode Progress C++

Showcasing my atrociously slow progress of plowing through leetcode questions in CPP.

Where are the files?

To find my corresponding submission of a problem, simply search (ctrl+f) for the problem index.

Finished Problems

Sub-Total: 47

Array
Number	Title	Init Date	Review Date	Special Notes
27	Remove Element	1/30	2/27		V
35	Search Insert Position	1/31			V
66	Plus One	2/2
88	Merge Sorted Array	2/3			V
118	Pascal's-Triangle	2/4
122	Best Time to Buy and Sell Stock II	2/5
167	Two Sum II - Input array is sorted	2/6			V
217	Contains-Duplicate	2/7
1480	Running Sum of 1d Array	3/10
1431	Kids With the Greatest Number of Candies	3/10
1470	Shuffle the Array	3/10
414	Third Maximum Number	3/10		sets
1672	Richest Customer Wealth	3/12
724*	Find Pivot Index	3/12		cannot reset left, right
1512	Number of Good Pairs	3/20
896	Monotonic Array	3/20
1365*	How Many Numbers Are Smaller Than the Current Number	3/23		Create lookup table O(n)
1*	Two Sum	3/23		Unordered map and find()
1773*	Count Items Matching a Rule	3/24		Lambda functions and count_if()
1313*	Decompress Run-Length Encoded List	3/25		vector.insert()
1389*	Create Target Array in the Given Order	3/26		vector.insert() or swap()
1486	XOR Operation in an Array	3/28
1588	Sum of All Odd Length Subarrays	3/28
1534	Count Good Triplets	3/30
999	Available Captures for Rook	3/30
1732	Find the Highest Altitude	3/31
1266	Minimum Time Visiting All Points	3/31
1252	Cells with Odd Values in a Matrix	4/12
1295	Find Numbers with Even Number of Digits	4/12
832	Flipping an Image	4/12
463*	Island Perimeter	4/16		Perimeter math
73*	Set Matrix Zeroes	5/14		O(1) Space (Last row)
238*	Product of Array Except Self	5/20		O(n) Time (2 pointer)
48*	Rotate Image	6/9		Rotation geometry	V
11*	Container With Most Water	6/11		2 Pointers
33*	Search in Rotated Sorted Array	6/12		2 Pointers	V
3*	Longest Substring Without Repeating Characters	6/28		Sliding window	V
15*	3Sum	7/10		2 Pointers	V
16*	3Sum Closet	7/10		2 Pointers	V
18*	4Sum	7/10		2 Pointers	V
26*	Remove Duplicates from Sorted Array	7/13		2 Pointers	V
80*	Remove Duplicates from Sorted Array II	9/3		2 Pointers	V
136*	Single Number	9/12		XOR	V
162*	Find Peak Element	9/18		Binary Search	V
137*	Single Number II	9/18		Count sum of bits for each digit	V
155*	Min Stack	9/15		Stack of pairs	V
169*	Majority Element	10/8		Boyer-Moore voting algorithm	V

Sub-Total: 8

Hash
Number	Title	Init Date	Review Date	Special Notes
771	Jewels and Stones	4/15
1748	Sum of Unique Elements	4/15
961	N-Repeated Element in Size 2N Array	4/16		unordered_set
1207	Unique Number of Occurrences	4/16		uset + umap
811*	Subdomain Visit Count	4/16		stoi, string::find()
1002*	Find Common Characters	4/16		2 Hash Tables (vector)
347*	Top K Frequent Elements	6/7		bucket sort (reverse vector)
49*	Group Anagrams	7/22		sort entry to place into bucket	V

Sub-Total: 12

List
Number	Title	Init Date	Review Date	Special Notes
2	Add Two Numbers	2/8
24	Swap Nodes in Pairs	2/8	5/17	Recursive
21	Merge Two Sorted Lists	2/9	2/28		V
141	Linked List Cycle	2/10	2/28	Fast + Slow	V
23	Merge K Sorted Lists	3/10		Priority Queue	V
206**	Reverse Linked List	5/17		Recursive/Graphical	V
148**	Sort List	5/18		Merge Sort Recursive	V
143*	Reorder List	6/7		Recursive
19*	Remove Nth Node From End of List	7/12		Fast + Slow	V
82*	Remove Duplicates from Sorted List	9/4			V
83*	Remove Duplicates from Sorted List II	9/4			V
142*	Linked List Cycle II	9/13		Floyd's Algorithm	V

Sub-Total: 15

Tree
Number	Title	Init Date	Review Date	Special Notes
94	Binary Tree Inorder Traversal	2/11	5/16
100	Same Tree	2/11		Recursive
101	Symmetric Tree	2/11		Recursive
102	Binary Tree Level Order Traversal	2/13		BFS + queue
107	Binary Tree Level Order Traversal II	2/13	5/14	BFS + queue / DFS
872	Leaf-Similar Trees	2/13		Recursive
530	Minimum Absolute Difference in BST	2/17		In-Order
700	Search in a Binary Search Tree	2/18		In-Order
589*	N-ary Tree Preorder Traversal	3/6		Pre-Order + iterative stack
938	Range Sum of BST	4/17		In-Order
617*	Merge Two Binary Trees	4/18		In-Order + new()
897*	Increasing Order Search Tree	4/19		In-Order + new()
1022*	Sum of Root To Leaf Binary Numbers	4/19		In-Order + pop sequence
95*	Unique Binary Search Trees II	5/16		Recursive Solution
208*	Implement Trie (Prefix Tree)	9/19		Recursive Struct (like AST)

Sub-Total: 22

DFS
Number	Title	Init Date	Review Date	Special Notes
733*	Flood Fill	2/15
547*	Number of Provinces	2/16
841*	Keys and Rooms	2/16
207*	Course Schedule	2/17		topological sort
39*	Combination Sum	2/22			V
687*	Longest Univalue Path	5/2
104*	Maximum Depth of Binary Tree	5/3
108*	Convert Sorted Array to Binary Search Tree	5/4
114**	Flatten Binary Tree to Linked List	5/6
257*	Binary Tree Paths	5/10
199*	Binary Tree Right Side View	5/11
491*	Increasing Subsequences	5/12
109*	Convert Sorted List to Binary Search Tree	5/14
128*	Longest Consecutive Sequence	6/6		unordered_set
297*	Serialize and Deserialize Binary Tree	6/6		stringstream
417*	Pacific Atlantic Water Flow	6/13
17*	Letter Combinations of a Phone Number	7/10			V
40*	Combination Sum II	7/14			V
46*	Permutations	7/21			V
78*	Subsets	8/28			V
90*	Subsets II	9/9			V
1239*	Maximum Length of a Concatenated String with Unique Characters	9/26			V

Sub-Total: 10

DP
Number	Title	Init Date	Review Date	Special Notes
53*	Maximum Subarray	2/1		i = max(i*m, i)	V
121*	Best Time to Buy and Sell Stock I	2/5
746*	Min Cost Climbing Stairs	3/2		i += i-1 + i-2
279*	Perfect Squares	5/13		min(i, i- JxJ)
309*	Best Time to Buy and Sell Stock with Cooldown	5/13		FSM
152*	Maximum Product Subarray	6/14		i = max(i*m, i) and swap
5*	Longest Palindromic Substring	6/30		4 patterns: a aa aba abba	V
55*	Jump Game	7/26			V
62*	Unique Paths	7/26			V
70*	Climbing Stairs	7/27			V

Sub-Total: 3

String
Number	Title	Init Date	Review Date	Special Notes
22*	Generate Parentheses	5/15		Recursion	V
13*	Roman to Integer	5/16		Unordered Map
20*	Valid Parentheses	7/12		Stack	V

Sub-Total: 4

Math
Number	Title	Init Date	Review Date	Special Notes
7*	Reverse Integer	6/30		Overflow check	V
9*	Palindrome Number	7/8			V
69*	Sqrt(x)	7/27		Binary Search	V
67*	Add Binary	9/26			V

Total: 121

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This page will be updated tentatively upon completion of solving more problems.

Last Update: 9/26/2021