文摘
Partially answering a question posed by Araujo, Morel, Sampaio, Soares, and Weber, we show that computing the geodetic hull number of a given class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0304397516302341&_mathId=si1.gif&_user=111111111&_pii=S0304397516302341&_rdoc=1&_issn=03043975&md5=4765fb4a04a44b8d3aaf57123a21e3a1" title="Click to view the MathML source">P9class="mathContainer hidden">class="mathCode">-free graph is NP-hard. Similarly, we show that computing the geodetic interval number of a given class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0304397516302341&_mathId=si132.gif&_user=111111111&_pii=S0304397516302341&_rdoc=1&_issn=03043975&md5=8c253ab9f5b7d5cf7230d080bbd10eea" title="Click to view the MathML source">P5class="mathContainer hidden">class="mathCode">-free graph is NP-hard. Furthermore, we show that the geodetic hull number can be computed in polynomial time for class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0304397516302341&_mathId=si169.gif&_user=111111111&_pii=S0304397516302341&_rdoc=1&_issn=03043975&md5=bc926664f7eb60bac6977e4d69ce2819" title="Click to view the MathML source">{paw,P5}class="mathContainer hidden">class="mathCode">-free graphs, triangle-free graphs in which every six vertices induce at most one class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0304397516302341&_mathId=si132.gif&_user=111111111&_pii=S0304397516302341&_rdoc=1&_issn=03043975&md5=8c253ab9f5b7d5cf7230d080bbd10eea" title="Click to view the MathML source">P5class="mathContainer hidden">class="mathCode">, and class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0304397516302341&_mathId=si4.gif&_user=111111111&_pii=S0304397516302341&_rdoc=1&_issn=03043975&md5=8a8650a96608018768adab553eb12b90" title="Click to view the MathML source">{C3,…,Ck−2,Pk}class="mathContainer hidden">class="mathCode">-free graphs for every integer k.