👇👇 Top 50 Basic DSA Problems 👇👇

1: Find the maximum element in an array. Hint Solve
2: Find the minimum element in an array. Hint Solve
3: Calculate the sum of elements in an array. Hint Solve
4: Reverse an array. Hint Solve
5: Rotate an array to the right by k positions. Hint Solve
6: Check if an array is sorted. Hint Solve
7: Find the frequency of an element in an array. Hint Solve
8: Find the majority element in an array (if it exists). Hint Solve
9: Find the intersection of two arrays. Hint Solve
10: Merge two sorted arrays. Hint Solve

11: Reverse a string. Hint Solve
12: Check if a string is a palindrome. Hint Solve
13: Find the longest substring without repeating characters. Hint Solve
14: Count the occurrences of a character in a string. Hint Solve
15: Check if two strings are anagrams of each other. Hint Solve
16: Implement a basic string compression algorithm. Hint Solve
17: Find the first non-repeating character in a string. Hint Solve

18: Implement a singly linked list. Hint Solve
19: Reverse a linked list. Hint Solve
20: Detect a cycle in a linked list. Hint Solve
21: Find the middle element of a linked list. Hint Solve
22: Merge two sorted linked lists. Hint Solve
23: Remove duplicates from a sorted linked list. Hint Solve
24: Add two numbers represented by linked lists. Hint Solve

25: Implement a stack using an array or linked list. Hint Solve
26: Implement a queue using an array or linked list. Hint Solve
27: Check for balanced parentheses using a stack. Hint Solve
28: Evaluate a postfix expression using a stack. Hint Solve
29: Implement min stack that supports finding min element in O(1) time. Hint Solve

30: Implement binary search in a sorted array. Hint Solve
31: Implement linear search in an unsorted array. Hint Solve
32: Implement bubble sort. Hint Solve
33: Implement selection sort. Hint Solve
34: Implement insertion sort. Hint Solve
35: Implement merge sort. Hint Solve
36: Implement quicksort. Hint Solve

37: Implement a binary search tree (BST). Hint Solve
38: Perform an inorder traversal of a binary tree. Hint Solve
39: Perform a preorder traversal of a binary tree. Hint Solve
40: Perform a postorder traversal of a binary tree. Hint Solve
41: Check if a binary tree is a binary search tree (BST). Hint Solve
42: Find the height (depth) of a binary tree. Hint Solve
43: Find the lowest common ancestor (LCA) of two nodes in a binary tree. Hint Solve
44: Serialize and deserialize a binary tree. Hint Solve

45: Implement a graph using adjacency matrix or adjacency list. Hint Solve
46: Perform a depth-first search (DFS) on a graph. Hint Solve
47: Perform a breadth-first search (BFS) on a graph. Hint Solve
48: Find shortest path b/w two nodes in weighted graph (Dijkstra's alg.). Hint Solve
49: Find minimum spanning tree of graph (Prim's or Kruskal's algorithm). Hint Solve
50: Detect if a directed graph has a cycle (using DFS or topological sorting). Hint Solve