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3 votes
1 answer
62 views

Greedy lemma Problem for matching spears to soldiers

The problem has $n$ spears and $n$ soldiers. Spears and soldiers have heights. We want to assign spears to soldiers such that the total height difference of spears and their assigned soldiers is ...
Yavuz Bozkurt's user avatar
1 vote
1 answer
248 views

Let $ G $ be a connected graph and $ C $ be an odd-length cycle in G. Show that if $ H $ has a perfect matching, then $ G $ has a perfect matching .

Let $ G $ be a connected graph and $ C $ be an odd-length cycle in G. We define graph $H$ as follows: $$ V (H) = {{(V (G) - V (C)) ∪ {c}}}, $$ where $ c $ is a new vertex that we add arbitrarily $$ E ...
MR_chep's user avatar
  • 141
2 votes
1 answer
845 views

The number of perfect matchings corresponds to the Matrix Permanent

I want to show that the number of perfect matchings in a bipartite graph is precisely the permanent of the adjacency matrix of the graph. This seems somehow quite natural to me. But how could I give ...
3nondatur's user avatar
  • 4,222
0 votes
2 answers
2k views

Proving that every connected graph of order 4 that is not $K_{1,3}$ has a perfect matching.

I am asked to prove two things: (a) Prove that every connected graph of order 4 that is not $K_{1,3}$ has a perfect matching. (b) Let G be a connected graph of even order. Prove that if G contains ...
Sam's user avatar
  • 1,088
1 vote
1 answer
943 views

All stable matchings of a given bipartite graph cover the same vertices.

I believe this proof is pretty obvious, since stable matchings saturate all of the vertices, right? Still I will give it a go: Let $M_1$ and $M_2$ be two matchings such that they don't cover the same ...
mandella's user avatar
  • 1,862
1 vote
3 answers
2k views

Stable Marriage / Stable Matching / Gale-Shapley where men rank a subset of women

Given n men and n women, preference rankings for the women, does Gale-Shapley still find a stable matching if the men only rank a subset of women. From this variation, it's possible that we end up ...
SleekPanther's user avatar