This is a challenge by LeetCode consisting of 30 daily problems over the month of June. A problem is added each day, and we have 24 hours to make a valid submission. I will be uploading my solutions in this repository after the deadline to make a valid submission for the given problem has passed.

• Day 1: Invert Binary Tree

  Recursive Inversion | Time: O(n) | Space: O(n)

• Day 2: Delete Node in a Linked List

  Exchanging Node Data | Time: O(1) | Space: O(1)

• Day 3: Two City Scheduling

  Dynamic Programming | Time: O(n^2) | Space: O(n^2) (Recursive Stack)

• Day 4: Inverse String

  Swapping Characters | Time: O(n) | Space: O(1)

• Day 5: Random Pick with Weight

  Discrete Distribution + Binary Search | Time: O(n) (Precomputation) + O(logn) (Function Call) | Space: O(n)

• Day 6: Queue Reconstruction by Height

  Sorting | Time: O(n^2) | Space: O(n)

• Day 7: Coin Change 2

  Knapsack | Time: O(n*m) | Space: O(n)

• Day 8: Power of Two

  Bitwise Operation | Time: O(1) | Space: O(1)

• Day 9: Is Subsequence

  Recursive Character Matching | Time: O(n) | Space: O(n) (Recursive Stack)

• Day 10: Search Insert Position

  Binary Search | Time: O(log(n)) | Space: O(1)

• Day 11: Sort Colors

  Dutch National Flag Problem | Time: O(n) | Space: O(1)

• Day 12: Insert Delete GetRandom O(1)

  Map + Vector Data Structure | Time: O(1)[Average Complexity] | Space: O(n)

• Day 13: Largest Divisible Subset

  Dynamic Programming (LIS) | Time: O(n^2) | Space: O(n)

• Day 14: Cheapest Flights Within K Stops

  Dynamic Programming | Time: O(n*k) | Space: O((n^2)*k)

• Day 15: Search In A Binary Search Tree

  Recursive Binary Search | Time: O(log(n)) | Space: O(log(n))

• Day 16: Validate IP Address

  Tokenizing String | Time: O(n) | Space: O(n)

• Day 17: Surrounded Regions

  DFS | Time: O(n) | Space: O(n) (Where 'n' is the number of nodes)

• Day 18: H-Index II

  Binary Search | Time: O(log(n)) | Space: O(1)

• Day 19: Longest Duplicate Substring

  Binary Search + Rabin-Karp Algorithm | Time: O(n(log(n))) | Space: O(n)

• Day 20: Permutation Sequence

  Factorials | Time: O(n) | Space: O(n^2) (Recursive Stack + Map)

• Day 21: Dungeon Game

  Dynamic Programming | Time: O(n*m) | Space: O(n)

• Day 22: Single Game II

  Bitmasking | Time: O(n) | Space: O(1)

• Day 23: Count Complete Tree Nodes

  Recursive Traversal | Time: O(n) | Space: O(log(n))

• Day 24: Unique Binary Search Trees

  Catalan Number | Time: O(n) | Space: O(n)

• Day 25: Find Duplicate Number

  Floyd's Tortoise and Hare Algorithm | Time: O(n) | Space: O(1)

• Day 26: Sum Root to Leaf Numbers

  DFS | Time: O(n) | Space: O(n)

• Day 27: Perfect Squares

  Dynamic Programming | Time: O(n^3/2) | Space: O(n)

• Day 28: Reconstruct Itinenary

  Hierholzer Algorithm | Time: O(E) (Number of edges) | Space: O(E*E)

• Day 29: Unique Paths

  Dynamic Programming | Time: O(n*m) | Space: O(n)

• Day 30: Word Search II

  Trie + DFS | Time: O(n^2 * m * s) | Space: O(n^2 * m * s) (DFS Recursive Depth + Words Size)