Doudou Hei

activity

20212025

collaborators

4 papers

math.CO2025

The generalized Turán number for K_3 in graphs without suspensions of a path on five vertices

Doudou Hei, Xinmin Hou, Yue Ma

Given graphs $H$ and $F$ , the generalized Turán number $\ex(n, H, F)$ is defined as the maximum number of copies of $H$ in an $n$ -vertex graph that contains no copy of $F$ . The sus…

math.CO2022

Minimizing the number of matchings of fixed size in a $K_{s}$ -saturated graph

Jiejing Feng, Doudou Hei, Xinmin Hou

For a fixed graph $F$ , a graph $G$ is said to be $F$ -saturated if $G$ does not contain a subgraph isomorphic to $F$ but does contain $F$ after the addition of any new edge. Let $M_…

math.CO2022

The cycle of length four is strictly $F$ -Turán-good

Doudou Hei, Xinmin Hou

Given an $(r + 1)$ -chromatic graph $F$ and a graph $H$ that does not contain $F$ as a subgraph, we say that $H$ is strictly $F$ -Turán-good if the Turán graph $T_{r} (n)$ is the unique…

math.CO2021

Some exact results of the generalized Turán numbers for paths

Doudou Hei, Xinmin Hou, Boyuan Liu

For graphs $H$ and $F$ with chromatic number $χ (F) = k$ , we call $H$ strictly $F$ -Turán-good (or $(H, F)$ strictly Turán-good) if the Turán graph $T_{k - 1} (n)$ is the unique $F$ -free…

The generalized Turán number for K_3 in graphs without suspensions of a path on five vertices

Minimizing the number of matchings of fixed size in a Ks​-saturated graph

The cycle of length four is strictly F-Turán-good

Some exact results of the generalized Turán numbers for paths

Minimizing the number of matchings of fixed size in a $K_{s}$ -saturated graph

The cycle of length four is strictly $F$ -Turán-good