Yacong Zhou

works on

oriented graphs 1 planar graphs 1 second neighbourhood conjecture 1 split graphs 1 triangle-free graphs 1

From the 1 of 9 linked papers with an AI index.

collaborators

9 papers

math.CO2026

Bounds on Odd and Odd-Even Induced Subgraphs

Qiwen Guo, Gregory Gutin, Yiming Hao +3

Let $G$ be an $n$ -vertex graph and let $ℓ : V (G) \to F_{2}$ prescribe degree parities. A set $S \subseteq V (G)$ is $ℓ$ -admissible if every $v \in S$ has degree congruent to…

math.CO2026

The optimal constant for minimum weight feedback arc sets in oriented graphs

Yacong Zhou

Let $D$ be an oriented graph (a digraph with no directed 2-cycles) with maximum degree $I^ \geq 1$ , equipped with nonnegative arc weights of total weight $w (D)$ , and let $\mathrm{fas…

math.CO2026

Weighted Counting Formula and $2 n /21$ Lower Bound for Induced Subgraphs with Prescribed Degree Parities

Gregory Gutin, Yiming Hao, Yacong Zhou

Let $G = (V, E)$ be a finite simple graph of order $n \geq 1$ , and let $ℓ : V \to {0, 1}$ be a prescribed parity labeling. A set $S \subseteq V$ is called $ℓ$ -admissible if $d_S(v)\e…

math.CO2026

On Seymour's and Sullivan's Second Neighbourhood Conjectures

Jiangdong Ai, Stefanie Gerke, Gregory Gutin +3

The paper investigates Seymour's and Sullivan's second neighbourhood conjectures for directed graphs, giving a condition based on the number of transitive triangles that ensures Su…

math.CO2026

A discrepancy dichotomy for 1-factorizations of signed complete bipartite graphs

Yisai Xue, Yacong Zhou

Given a signing $I ¨ : E (K_{n, n}) \to {- 1, + 1}$ of the complete bipartite graph, when does $K_{n, n}$ admit a $1$ -factorization in which every perfect matching has discrepancy bou…

math.CO2026

Forward Arc Maximization for Hamilton Oriented Cycles and Paths in Generalizations of Tournaments

Q. Guo, G. Gutin, Y. Lan +3

Gishboliner, Krivelevich, and Michaeli (2023) conjectured the following generalization of Dirac's theorem: If the minimum degree $I^´$ of an $n$ -vertex oriented graph $G$ is greater…

Bounds on Odd and Odd-Even Induced Subgraphs

The optimal constant for minimum weight feedback arc sets in oriented graphs

Weighted Counting Formula and 2n/21 Lower Bound for Induced Subgraphs with Prescribed Degree Parities

On Seymour's and Sullivan's Second Neighbourhood Conjectures

A discrepancy dichotomy for 1-factorizations of signed complete bipartite graphs

Forward Arc Maximization for Hamilton Oriented Cycles and Paths in Generalizations of Tournaments

Weighted Counting Formula and $2 n /21$ Lower Bound for Induced Subgraphs with Prescribed Degree Parities