Maximum number of subtrees in cacti and block graphs
被引:4
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作者:
Li, Jie
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机构:
Nanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Comp Air Vehicles, MIIT Key Lab Math Modelling & High Performance, Nanjing 210016, Peoples R ChinaNanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Li, Jie
[1
,2
]
Xu, Kexiang
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h-index: 0
机构:
Nanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Comp Air Vehicles, MIIT Key Lab Math Modelling & High Performance, Nanjing 210016, Peoples R ChinaNanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Xu, Kexiang
[1
,2
]
Zhang, Tianli
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h-index: 0
机构:
Nanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Comp Air Vehicles, MIIT Key Lab Math Modelling & High Performance, Nanjing 210016, Peoples R ChinaNanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Zhang, Tianli
[1
,2
]
Wang, Hua
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机构:
Georgia Southern Univ, Dept Math Sci, Statesboro, GA 30460 USANanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Wang, Hua
[3
]
Wagner, Stephan
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机构:
Uppsala Univ, Dept Math, S-75106 Uppsala, Sweden
Stellenbosch Univ, Dept Math Sci, ZA-7602 Stellenbosch, South AfricaNanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
Wagner, Stephan
[4
,5
]
机构:
[1] Nanjing Univ Aeronaut & Astronaut, Coll Math, Nanjing 210016, Peoples R China
[2] Comp Air Vehicles, MIIT Key Lab Math Modelling & High Performance, Nanjing 210016, Peoples R China
[3] Georgia Southern Univ, Dept Math Sci, Statesboro, GA 30460 USA
[4] Uppsala Univ, Dept Math, S-75106 Uppsala, Sweden
[5] Stellenbosch Univ, Dept Math Sci, ZA-7602 Stellenbosch, South Africa
Number of subtrees;
Cactus graph;
Block graph;
WIENER INDEX;
TREES;
D O I:
10.1007/s00010-022-00879-1
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
For a graph G, we denote by N(G) the number of non-empty subtrees of G. As a topological index based on counting, N(G) has some correlations to other well studied topological indices, including the Wiener index W(G). In this paper we characterize the extremal graphs with the maximum number of subtrees among all cacti of order n with k cycles. Similarly, the extremal graphs with the maximum number of subtrees among all block graphs of order n with k blocks are also determined and shown to have the minimum Wiener index within the same collection of graphs. Analogous results are also obtained for the number of connected subgraphs C(G). Finally, a general question is posed concerning the relation between the number of subtrees and the Wiener index of graphs.
机构:
Univ Pannonia, Fac Informat Technol, Egyet U 10, H-8200 Veszprem, HungaryUniv Pannonia, Fac Informat Technol, Egyet U 10, H-8200 Veszprem, Hungary
Bujtas, Csilla
Jakovac, Marko
论文数: 0引用数: 0
h-index: 0
机构:
Univ Maribor, Fac Nat Sci & Math, Koroska Cesta 160, Maribor 2000, Slovenia
Inst Math Phys & Mech, Jadranska 19, Ljubljana 1000, SloveniaUniv Pannonia, Fac Informat Technol, Egyet U 10, H-8200 Veszprem, Hungary
机构:
Huaiyin Inst Technol, Fac Math & Phys, Huaian 223003, Jiangsu, Peoples R ChinaHuaiyin Inst Technol, Fac Math & Phys, Huaian 223003, Jiangsu, Peoples R China