Set Maximum matching to fill in the blanks (at the end of a task) on the graph.
-
When considering the maximum matching on a graph, a point with rank 1 can be considered to be included in the maximum matching
-
The edge containing the point with rank 1 is called the “end edge”, and the edge containing the other side of the edge is called the “next edge”.
- The next edge is zero or more in the general graph
-
When you choose a certain maximum matching
- 1: If neither the end edge nor the next edge is selected (or the next edge does not exist), then selecting the end edge increases the number of matches by 1
- In other words, it was never a maximum match to begin with.
- 2: When an edge is unselected and the next edge is selected, swapping selections does not increase or decrease
- Thus, the exchanged ones are also the maximum matching
- 3: Neither the end edge nor the next edge is selected for matching.
- From 1 and 2, some of the largest matches always have end edges selected.
- So you can select an edge and remove it.
- In restricted graphs, this “edge of a blade removal” results in a new [edge of a blade
- It does not hold true for general graphs.
- Composed at the time of the tree: m_solutions2019D.
- Graphs whose maximal vertex is always rank 1: AGC029B.
- dominoes falling down a hill Everything will be resolved.
- 1: If neither the end edge nor the next edge is selected (or the next edge does not exist), then selecting the end edge increases the number of matches by 1
This page is auto-translated from /nishio/グラフ上の最大マッチングを端から埋める using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I’m very happy to spread my thought to non-Japanese readers.