LeetCode75 🔗

Arrays/Strings

Problem	Difficulty		Time Complexity	Space Complexity
Merge Strings Alternately	Easy	Solution	O(n)	O(1)
Greatest Common Divisor of Strings	Easy	Solution	O(m+n+logmin(m,n))	O(m + n)
Kids With the Greatest Number of Candies	Easy	solution	O(n)	O(1)
Can Place Flowers	Easy	Solution	O(n)	O(1)
Reverse Vowels of a String	Easy	Solution	O(log n)	O(1)
Reverse Words in a String	Medium	Solution	O(n)	O(n)
Product of Array Except Self	Medium	Solution	O(n)	O(1)
Increasing Triplet Subsequence	Medium	Solution	O(n)	O(1)
String Compression	Medium	Solution	O(n)	O(1)

Two Pointers

Problem	Difficulty		Time Complexity	Space Complexity
Move Zeroes	Easy	Solution	O(n)	O(1)
Is Subsequence	Easy	Solution	O(n)	O(1)
Container With Most Water	Medium	Solution	O(n)	O(1)
Max Number of K-Sum Pairs	Medium	Solution	O(n log n) and O(n)	O(1)

Sliding Window

Problem	Difficulty		Time Complexity	Space Complexity
Maximum Average Subarray I	Easy	Solution	O(n)	O(1)
Maximum Number of Vowels in a Substring of Given Length	Medium	Solution	O(n)	O(1)
Max Consecutive Ones III	Medium	Solution	O(n)	O(1)
Longest Subarray of 1's After Deleting One Element	Medium	Solution	O(n)	O(1)

Prefix Sum

Problem	Difficulty		Time Complexity	Space Complexity
Find the Highest Altitude	Easy	Solution	O(n)	O(1)
Find the Pivot Index	Easy	Solution	O(n)	O(1)

Hash Map / Set

Problem	Difficulty		Time Complexity	Space Complexity
Find the Difference of Two Arrays	Easy	Solution	O(n)	O(1)
Unique Number of Occurrences	Easy	Solution	O(n)	O(1)
Determine if Two Strings Are Close	Medium	Solution	O(n)	O(1)
Equal Row and Column Pairs	Medium	Solution	O(n)	O(1)

Stacks

Problem	Difficulty		Time Complexity	Space Complexity
Removing Stars From a String	Medium	Solution	O(n)	O(1)
Asteroid Collision	Medium	Solution	O(n)	O(1)
Decode String	Medium	Solution	O(n)	O(n)

Queues

Problem	Difficulty		Time Complexity	Space Complexity	Visit Again
Number of Recent Calls	Easy	Solution	O(1)	O(1)
Dota 2 Senate	Medium	Solution	O(n)	O(1)	Must Redo

Linked Lists

Problem	Difficulty		Time Complexity	Space Complexity
Delete the Middle Node of a Linked List	Medium	Solution	O(log n)	O(1)
Odd Even Linked List	Medium	Solution	O(log n)	O(1)
Reverse Linked List	Easy	Solution	O(n)	O(1)
Maximum Twin Sum of a Linked List	Medium	Solution	O(n)	O(1)

Binary Tree (DFS)

Problem	Difficulty		Time Complexity	Space Complexity
Maximum Depth of Binary Tree	Easy	Solution	O(n)	O(1)
Leaf Similar Trees	Easy	Solution	O(n)	O(n)
Count Good Nodes in Binary Tree	Medium	Solution	O(n)	O(1)
Path Sum III	Medium	Solution	O(n)	O(n)
Longest ZigZag Path in a Binary Tree	Medium	Solution	O(n)	O(n)
Lowest Common Ancestor of a Binary Tree	Medium	Solution	O(n)	O(n)

Binary Tree (BFS)

Problem	Difficulty		Time Complexity	Space Complexity
Binary Tree Right Side View	Medium	Solution	O(n)	O(1)
Maximum Level Sum of a Binary Tree	Medium	Solution	O(n)	O(1)

Binary Search Tree

Problem	Difficulty		Time Complexity	Space Complexity
Search in a Binary Search Tree	Easy	Solution	O(n)	O(1)
Delete Node in a BST	Medium	Solution	O(n)	O(1)

Graphs - DFS

I need to re-do this. Too confusing. Maybe redo and understand how to solve these

Problem	Difficulty		Time Complexity	Space Complexity
Keys and Rooms	Medium	Solution	O(n)	O(n)
Number of Provinces	Medium	Solution	O(n)	O(n)
Reorder Routes to Make All Paths Lead to the City Zero	Medium	Solution	O(n)	O(n)
Evaluate Division	Medium	Solution	O(n)	O(n)

Graphs - BFS

Problem	Difficulty		Time Complexity	Space Complexity
Nearest Exit from Entrance in Maze	Medium	Solution	O(m x n)	O(m x n)
Rotting Oranges	Medium	Solution	O(m x n)	O(m x n)