LinkedList
LinkedList in DSA (Java)
Master pointer-based data structures for efficient insertions and deletions.
📌 Topics Covered
🚀 Introduction
LinkedList is a dynamic data structure where elements are connected using pointers instead of contiguous memory.
💡 Key Insight: Fast insertion & deletion, slow random access.
⚡ Basic Operations
- Insertion (beginning, middle, end)
- Deletion
- Traversal
🔗 Types of LinkedList
- Singly LinkedList
- Doubly LinkedList
- Circular LinkedList
🧪 Important Questions
ArrayList vs LinkedList
ArrayList → fast access, LinkedList → fast insert/delete
Reverse LinkedList
while (current != null) {
next = current.next;
current.next = prev;
prev = current;
current = next;
}
Detect Cycle
while (fast != null && fast.next != null) {
slow = slow.next;
fast = fast.next.next;
if (slow == fast) return true;
}
Find Middle
while (fast != null && fast.next != null) {
slow = slow.next;
fast = fast.next.next;
}
Merge Two Lists
if (l1.data < l2.data) {
l1.next = merge(l1.next, l2);
return l1;
}
☕ Java Implementation
class Node {
int data;
Node next;
}
🎯 Conclusion
LinkedList is essential for mastering pointer-based problems and is frequently asked in interviews.