Discrete Mathematics YMT211 · Fall 2026 Assoc. Prof. Ferhat Uçar
15 Graphs Monday, December 28, 2026

Connectivity, Coloring and Trees · Project Demo Day

Paths and connectivity, graph coloring, and trees. Project demos in the second half.

ReadRosen 10.4, 10.8, 11.1 >_ Lab 13: Coloring an Exam Timetable

Learning objectives

By the end of this week you can:

  • 1 Decide connectivity and find connected components.
  • 2 Explain Euler and Hamilton paths and when they exist.
  • 3 Color graphs, compute simple chromatic numbers and apply coloring to scheduling.
  • 4 Use the properties of trees: n vertices, n − 1 edges, unique paths.
  • 5 Present your semester project clearly in five minutes.

★ the wow moment

Four colors are enough for any map, and the proof needed a computer.

The four color theorem was proved in 1976 by checking about 1,500 cases by computer, the first famous computer-assisted proof. Graph coloring also schedules your exams and assigns CPU registers in every compiler.

Topics

  • Paths, connectivity, components
  • Euler and Hamilton paths
  • Graph coloring and chromatic number
  • Trees and spanning trees
  • Project demo day

Before class

  • Skim Rosen 10.4, 10.8, 11.1 (20 minutes is enough; we go through it together).
  • Bring paper and a pen: part of every lecture is solving by hand.

In industry

  • Scheduling

    Exam timetables: courses are vertices, shared students are edges, time slots are colors.

  • Compilers

    Register allocation colors an interference graph so that variables share CPU registers safely.

  • File systems and data

    Folders, JSON documents and HTML pages are trees; Huffman trees compress files.

Lab 13: Coloring an Exam Timetable

Build the conflict graph of real courses and color it greedily to produce an exam schedule.

due Fri, Jan 1 · 23:59 · 100 points · opens in week 15

Go deeper

Tags:connectivityEulerHamiltoncoloringchromatic numbertreespanning treeproject