Class Log
- Wednesday, 8/28:
Handed out handouts and basic info about the class. Described some
basic problems from which graphs arrise. Started with definitions:
graph, simple graph, bipartite graph, complement, neighbor, clique,
independent set, chromatic number.
- Friday, 8/30:
Defined some basic graphs (Kn, Cn,
Pn), definitions of subgraphs, isomorphism,
connected graphs, self-complementary graphs.
- Monday, 9/2:
Labor
Day -
- Wednesday, 9/4:
Decompositions, Petersen graph and its properties, adjacency matrix,
incidence matrix.
- Friday, 9/6:
Definitions of walks, trails and paths, components, König
Theorem (characterization of bip. graphs), cut-edges,
characterization of cut-edges.
- Monday, 9/9:
walks, trails, Eulerian trails, Eulerian graphs (necessary and
sufficient condition), degree-sum formula and applications.
- Wednesday, 9/11:
hypercube Qk and its properties, counting 6-cycles
in Petersen graph, extremal problems.
- Friday, 9/13:
existence of a bip. subgraph of a simple graph G
with at least e(G)/2 edges, Mentel's Theorem, degree
sequences, graphic sequences, Havel-Hakimi Theorem, definition of
directed graphs.
- Monday, 9/16:
1.4 Directed graphs: basic definitions, connectivity (strong
components, Eulerian digraph), de Bruijn cycles, tournaments and
kings.
- Wednesday, 9/18:
2.1 Trees and Distance: basic definitions (tree, forest, spanning
subgraph), characterization of trees (Lemma 2.1.3, Theorem 2.1.4),
embedding of trees (Proposition 2.1.8)
- Friday, 9/20:
- Monday, 9/23:
Pr\uuml;fer Code, counting spanning trees, Matrix Tree Theorem.
- Wednesday, 9/25:
Kruskal's Algorithm and its proof, Prim's Algorithm,
Dijkstra's ALgorithm.
- Friday, 9/27:
Proof of Dijkstra's Algorithm, Breadth-First Search, Chapter 3. Matching
and Factors: definitions (perfect, maximal, maximum) matching, alternating
paths, augmenting paths, Berge's Theorem.
- Monday, 9/30:
Proof of Berge's Theorem, matchings in bipartite graphs, Hall's Theorem
and its proof.
- Wednesday, 10/2:
König-Egerváry Theorem, edge and vertex covers, independent
sets and their relations.
- Friday, 10/4:
Gallai's Theorem and its proof, maximum bip. matching (Augmenting Path
Algorithm), stable matchings.
- Monday, 10/7:
Proposing algorithm for the stable matching and its proof, matchings in
general graphs, Tutte's Theorem.
- Wednesday, 10/9:
Proof of Tutte's Theorem, Berge-Tutte Formula, Peterson Theorem.
- Friday, 10/11:
2-factors in regular graphs, definitions of connectivity, connectivity of hypercube.
- Monday, 10/14:
Harary graphs, edge-connectivity, relations between vertex-, edge-connectivity and min. degree,
- Wednesday, 10/16:
bonds, blocks, 2-connected graphs and internally disjoint paths
- Friday, 10/18:
Expansion lemma, equivalent conditions for 2-connectdness, ear decompositions.
- Monday, 10/14:
closed ear decomposition and 2-edge-connected graphs, network and flows,
f-augmenting paths and max. flows.
Last changed on October 21, 2002.