# Tournaments

## Monochromatic reachability or rainbow triangles ★★★

Author(s): Sands; Sauer; Woodrow

In an edge-colored digraph, we say that a subgraph is *rainbow* if all its edges have distinct colors, and *monochromatic* if all its edges have the same color.

**Problem**Let be a tournament with edges colored from a set of three colors. Is it true that must have either a rainbow directed cycle of length three or a vertex so that every other vertex can be reached from by a monochromatic (directed) path?

Keywords: digraph; edge-coloring; tournament

## Decomposing an even tournament in directed paths. ★★★

Author(s): Alspach; Mason; Pullman

**Conjecture**Every tournament on an even number of vertices can be decomposed into directed paths.

Keywords:

## Edge-disjoint Hamilton cycles in highly strongly connected tournaments. ★★

Author(s): Thomassen

**Conjecture**For every , there is an integer so that every strongly -connected tournament has edge-disjoint Hamilton cycles.

Keywords:

## Partitionning a tournament into k-strongly connected subtournaments. ★★

Author(s): Thomassen

**Problem**Let be positve integer Does there exists an integer such that every -strong tournament admits a partition of its vertex set such that the subtournament induced by is a non-trivial -strong for all .

Keywords:

## Decomposing k-arc-strong tournament into k spanning strong digraphs ★★

Author(s): Bang-Jensen; Yeo

**Conjecture**Every k-arc-strong tournament decomposes into k spanning strong digraphs.

Keywords: