Master DSA in Java in One Page (Ultimate Cheatsheet for Beginners & Interviews)

If you are learning Java and struggling with Data Structures & Algorithms (DSA)… you're not alone.

Most people spend months jumping between tutorials, videos, and notes but still feel confused.

So I created something simple
A DSA in Java Cheatsheet that helps you revise everything quickly.

Why This Cheatsheet?

Because DSA is not about memorizing…
It’s about quick understanding + smart revision.

This cheatsheet covers all the must-know topics in one place

1. Arrays

int[] arr = {1, 2, 3, 4};

// Traversal
for(int i = 0; i < arr.length; i++){
System.out.println(arr[i]);
}

Time Complexity: O(n)

2. Linked List

class Node {
int data;
Node next;
}

Types:

• Singly Linked List
• Doubly Linked List

3. Stack (LIFO)

Stack stack = new Stack<>();

stack.push(10);
stack.pop();
stack.peek();

4. Queue (FIFO)

Queue q = new LinkedList<>();

q.add(10);
q.remove();

5. Trees (Binary Tree)

Important Traversals:

• Inorder
• Preorder
• Postorder

6. Graphs

Most important:

• BFS (Breadth First Search)
• DFS (Depth First Search)

8. Searching

// Binary Search
int mid = (low + high) / 2;

Faster than Linear Search (O(log n))

Want More?

I share Full Tutorials and practical coding content Exercises, Interview:
🌐 https://www.quipoin.com/tutorial/data-structure-with-java