ma'am audrey's lessons
ITC 120

Data Structures and Algorithms

BSIT 2nd Year · A.Y. 2026–2027, 1st Semester

0123arraylinked listmapstackqueuetreegraph
Prelim topics2 units · 6 lessons

Start here. These lessons are the base for everything after them.

Unit 02 · 4 lessons

Linear data structures

  1. 1 Arrays: the four operationsData structureAlgorithmAccess, traversal, insertion, and deletion. Watch values shift, step by step.
  2. 2 Linked listsData structureAlgorithmNodes and references in Java. Insert and delete by changing arrows, and see what goes wrong in the wrong order.
  3. 3 StacksData structureLast in, first out, like a pile of plates. Push, pop, and peek: traces, a walkthrough, and a stack in Java using an array.
  4. 4 QueuesData structureFirst in, first out, like a canteen line. Enqueue and dequeue with a linked list, then stacks vs. queues side by side.
Midterm topics2 units · 8 lessons

Everything you need for the midterm exam. Go in order: each lesson builds on the one before it.

Unit 03 · 6 lessons

Trees and binary search trees

  1. 1 Trees and binary treesData structureRoot, parent, child, leaf, depth, height. Tap any node to see its family.
  2. 2 Binary search trees and BST searchData structureAlgorithmThe BST rule, searching by hand, and the search method in Java.
  3. 3 BST insertionAlgorithmInserting by hand, then the insert method in Java. Search, then attach at the null spot. Move current vs. connect a new node.
  4. 4 Tree traversalsAlgorithmPre-order, in-order, and post-order, step by step.
  5. 5 Recursion and traversal codeTechniqueBase case, recursive case, and the call stack. Traversals and insert in Java.
  6. 6 BST deletionAlgorithmThe three cases, the next value, and deleteRec in Java.
Final topics6 units · 10 lessons

After the midterm: graphs, sets, maps, searching, sorting, hashing, and algorithm complexity.

Unit 10 · 1 lesson

Algorithm complexity analysis

  1. 1 Algorithm complexity analysisComing soon