Yandong Bai

activity

20112026

most citedCharacterizing and recognizing exact-distance squares of graphs

3 citations · 6 across the 15 of their papers we have counts for

collaborators

18 papers

math.CO2026

Towards a strengthening of the second neighborhood conjecture

Yandong Bai, Binlong Li, Boram Park

A longstanding conjecture of Seymour, called Seymour's second neighborhood conjecture, states that every oriented graph $D$ contains a vertex $x$ with $|N^{++}_D(x)|\geq |N^{+}_D(x…

math.CO2026

Typical intersecting families are trivial

Yandong Bai, Haoyun Gu, Wenston J. T. Zang

We study the counting problem for non-uniform intersecting families in extremal set theory. Let $J (n, k)$ denote the number of intersecting families $F \subset 2^{[n]}$ suc…

math.CO2026

On 2-connected graphs without cycles of length 1 modulo 3

Yandong Bai, Hojin Chu, Binlong Li +2

Burr and Erdős conjectured in 1976 that for all integers $k > ℓ \geq 0$ such that $k Z + ℓ$ contains an even integer, every $n$ -vertex graph without cycles of length $\ell…

math.CO2026

Cross-intersecting families with covering number constraints

Yandong Bai, Haoyun Gu

Two families $F$ and $G$ are cross-intersecting if every set in $F$ intersects every set in $G$ . The covering number $τ (F)$ of a f…

math.CO2025

Cycle lengths in graphs of given minimum degree

Yandong Bai, Andrzej Grzesik, Binlong Li +1

We prove that if $G$ is a 2-connected graph with minimum degree at least $k ⩾ 4$ , then (1) $G$ contains $k$ cycles whose lengths form an arithmetic progression with common d…

math.CO2025

On graphs without cycles of length 1 modulo 3

Yandong Bai, Binlong Li, Yufeng Pan +1

Burr and Erdős conjectured in 1976 that for every two integers $k > ℓ ⩾ 0$ satisfying that $k Z + ℓ$ contains an even integer, an $n$ -vertex graph containing no cy…

math.CO2024

Vertex-disjoint cycles of different lengths in tournaments

Yandong Bai, Wenpei Jia

Bermond and Thomassen conjectured in 1981 that every digraph with minimum outdegree at least $2 k - 1$ contains $k$ vertex-disjoint cycles,here $k$ is a positive integer. Lichiardopol…

math.CO2022★ 3 cited

Characterizing and recognizing exact-distance squares of graphs

Yandong Bai, Pedro P. Cortés, Reza Naserasr +1

For a graph $G = (V, E)$ , its exact-distance square, $G^{[♯2]}$ , is the graph with vertex set $V$ and with an edge between vertices $x$ and $y$ if and only if $x$ and $y$ have d…

cs.CC2019

Safe sets in digraphs

Yandong Bai, Jørgen Bang-Jensen, Shinya Fujita +1

A non-empty subset $S$ of the vertices of a digraph $D$ is called a {\it safe set} if \begin{itemize} \item[(i)] for every strongly connected component $M$ of $D - S$ , there exists a…

math.CO2018

Uniform sets in a family with restricted intersections

Yandong Bai, Binlong Li, Jiuqiang Liu +1

Let $F$ be a family of subsets of $[n] = {1, \dots, n}$ and let $L$ be a set of nonnegative integers. The family $F$ is \emph{ $L$ -intersecting} if $|F\cap F'|\in…

math.CO2018

A note on hypergraph colorings

Yandong Bai

Let $t ⩾ 2$ and $s ⩾ 1$ be two integers. Define a $(t, s)$ -coloring of a hypergraph to be a coloring of its vertices using $t$ colors such that each color appears on e…

math.CO2018

Connected $k$ -factors in bipartite graphs

Yandong Bai, Binlong Li

Let $k, l$ be two positive integers. An $S_{k, l}$ is a graph obtained from disjoint $K_{1, k}$ and $K_{1, l}$ by adding an edge between the $k$ -degree vertex in $K_{1, k}$ and the $l$ -…

math.CO2018★ 1 cited

On the number of vertex-disjoint cycles in digraphs

Yandong Bai, Yannis Manoussakis

Let $k$ be a positive integer. Bermond and Thomassen conjectured in 1981 that every digraph with minimum outdegree at least $2 k - 1$ contains $k$ vertex-disjoint cycles. It is famous…

math.CO2018★ 1 cited

Rainbow triangles in arc-colored tournaments

Wei Li, Shenggui Zhang, Yandong Bai +1

Let $T_{n}$ be an arc-colored tournament of order $n$ . The maximum monochromatic indegree $Δ^{- m o n} (T_{n})$ (resp. outdegree $Δ^{+ m o n} (T_{n})$ ) of $T_{n}$ is the maximum number of…

math.CO2018

Kernels by rainbow paths in arc-colored tournaments

Yandong Bai, Binlong Li, Shenggui Zhang

For an arc-colored digraph $D$ , define its {\em kernel by rainbow paths} to be a set $S$ of vertices such that (i) no two vertices of $S$ are connected by a rainbow path in $D$ , an…

math.CO2017

On splitting digraphs

Donglei Yang, Yandong Bai, Guanghui Wang +1

In 1995, Stiebitz asked the following question: For any positive integers $s, t$ , is there a finite integer $f (s, t)$ such that every digraph $D$ with minimum out-degree at least $f(…

math.CO2017

Kernels by properly colored paths in arc-colored digraphs

Yandong Bai, Shinya Fujita, Shenggui Zhang

A {\em kernel by properly colored paths} of an arc-colored digraph $D$ is a set $S$ of vertices of $D$ such that (i) no two vertices of $S$ are connected by a properly colored dire…

math.CO2011★ 1 cited

Covering the edges of digraphs in $D (3, 3)$ and $D (4, 4)$ with directed cuts

Yandong Bai, Binlong Li, Shenggui Zhang

For nonnegative integers $k$ and $l$ , let $D (k, l)$ denote the family of digraphs in which every vertex has either indegree at most $k$ or outdegree at most $l$ . In this p…

Towards a strengthening of the second neighborhood conjecture

Typical intersecting families are trivial

On 2-connected graphs without cycles of length 1 modulo 3

Cross-intersecting families with covering number constraints

Cycle lengths in graphs of given minimum degree

On graphs without cycles of length 1 modulo 3

Vertex-disjoint cycles of different lengths in tournaments

Characterizing and recognizing exact-distance squares of graphs

Safe sets in digraphs

Uniform sets in a family with restricted intersections

A note on hypergraph colorings

Connected k-factors in bipartite graphs

On the number of vertex-disjoint cycles in digraphs

Rainbow triangles in arc-colored tournaments

Kernels by rainbow paths in arc-colored tournaments

On splitting digraphs

Kernels by properly colored paths in arc-colored digraphs

Covering the edges of digraphs in D(3,3) and D(4,4) with directed cuts

Connected $k$ -factors in bipartite graphs

Covering the edges of digraphs in $D (3, 3)$ and $D (4, 4)$ with directed cuts