All Questions
Tagged with extremal-graph-theory combinatorial-optimization
4 questions with no upvoted or accepted answers
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Size of set of positive integers no sum of two distinct elements giving square
Question: find the size of a maximal subset $A$ of $[n]=\{1,\cdots,n\}$ satisfying that for any distinct elements $x,y\in A$, $x+y$ is not a perfect square.
Consider a graph with $n$ vertices: $x$ and ...
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What is the optimal upper bound of $|T_1|+|T_2|+|T_3|$ if $T_1, T_2, T_3$ are trees covering a planar graph
By a classical theorem of Nash-Williams, the edges of every connected $n$-vertex planar graph can be covered by three trees $T_1,T_2$ and $T_3$. Does anyone know of any results from an article or a ...
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Estimates for the drop in the sum of all pairwise weighted distances effected by a decrease of the weight of an edge
Consider simple connected undirected graphs $G = (V, E)$ equipped with a function $w\colon E\rightarrow \{x\in \mathbb{R}\colon x\geq 0\}$.
Define a function $d_{G,w}\colon V\times V\rightarrow\...
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Topology of densest graphs whose optimal $3D$-matching can be calculated efficiently
let $A=\lbrace a_1,\,\dots,\,a_k\rbrace $ and $B=\lbrace b_1,\,\dots,\,b_{2k}\rbrace,\ A\cap B=\emptyset$ be be a partition of a graph's vertex set $V$, i.e. $V\,=\,A\cup B$.
Question:
has $G:=\...