{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T07:54:35Z","timestamp":1758268475354,"version":"3.37.3"},"reference-count":31,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2022,7,24]],"date-time":"2022-07-24T00:00:00Z","timestamp":1658620800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2022,7,24]],"date-time":"2022-07-24T00:00:00Z","timestamp":1658620800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100002428","name":"Austrian Science Fund","doi-asserted-by":"publisher","award":["P29355-N35"],"award-info":[{"award-number":["P29355-N35"]}],"id":[{"id":"10.13039\/501100002428","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Comb Optim"],"published-print":{"date-parts":[[2022,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The <jats:italic>k<\/jats:italic>-cardinality assignment (<jats:italic>k<\/jats:italic>-assignment, for short) problem asks for finding a minimal (maximal) weight of a matching of cardinality <jats:italic>k<\/jats:italic> in a weighted bipartite graph <jats:inline-formula><jats:alternatives><jats:tex-math>$$K_{n,n}$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:msub>\n                    <mml:mi>K<\/mml:mi>\n                    <mml:mrow>\n                      <mml:mi>n<\/mml:mi>\n                      <mml:mo>,<\/mml:mo>\n                      <mml:mi>n<\/mml:mi>\n                    <\/mml:mrow>\n                  <\/mml:msub>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula>, <jats:inline-formula><jats:alternatives><jats:tex-math>$$k \\le n$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>k<\/mml:mi>\n                    <mml:mo>\u2264<\/mml:mo>\n                    <mml:mi>n<\/mml:mi>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula>. Here we are interested in computing the sequence of all <jats:italic>k<\/jats:italic>-assignments, <jats:inline-formula><jats:alternatives><jats:tex-math>$$k=1,\\ldots ,n$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>k<\/mml:mi>\n                    <mml:mo>=<\/mml:mo>\n                    <mml:mn>1<\/mml:mn>\n                    <mml:mo>,<\/mml:mo>\n                    <mml:mo>\u2026<\/mml:mo>\n                    <mml:mo>,<\/mml:mo>\n                    <mml:mi>n<\/mml:mi>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula>. By applying the algorithm of Gassner and Klinz (2010) for the parametric assignment problem one can compute in time <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\mathcal {O}}(n^3)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>O<\/mml:mi>\n                    <mml:mo>(<\/mml:mo>\n                    <mml:msup>\n                      <mml:mi>n<\/mml:mi>\n                      <mml:mn>3<\/mml:mn>\n                    <\/mml:msup>\n                    <mml:mo>)<\/mml:mo>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> the set of <jats:italic>k<\/jats:italic>-assignments for those integers <jats:inline-formula><jats:alternatives><jats:tex-math>$$k \\le n$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>k<\/mml:mi>\n                    <mml:mo>\u2264<\/mml:mo>\n                    <mml:mi>n<\/mml:mi>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> which refer to essential terms of the full characteristic maxpolynomial <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\bar{\\chi }}_{W}(x)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:msub>\n                      <mml:mover>\n                        <mml:mrow>\n                          <mml:mi>\u03c7<\/mml:mi>\n                        <\/mml:mrow>\n                        <mml:mrow>\n                          <mml:mo>\u00af<\/mml:mo>\n                        <\/mml:mrow>\n                      <\/mml:mover>\n                      <mml:mi>W<\/mml:mi>\n                    <\/mml:msub>\n                    <mml:mrow>\n                      <mml:mo>(<\/mml:mo>\n                      <mml:mi>x<\/mml:mi>\n                      <mml:mo>)<\/mml:mo>\n                    <\/mml:mrow>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> of the corresponding max-plus weight matrix <jats:italic>W<\/jats:italic>. We show that <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\bar{\\chi }}_{W}(x)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:msub>\n                      <mml:mover>\n                        <mml:mrow>\n                          <mml:mi>\u03c7<\/mml:mi>\n                        <\/mml:mrow>\n                        <mml:mrow>\n                          <mml:mo>\u00af<\/mml:mo>\n                        <\/mml:mrow>\n                      <\/mml:mover>\n                      <mml:mi>W<\/mml:mi>\n                    <\/mml:msub>\n                    <mml:mrow>\n                      <mml:mo>(<\/mml:mo>\n                      <mml:mi>x<\/mml:mi>\n                      <mml:mo>)<\/mml:mo>\n                    <\/mml:mrow>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> is in full canonical form, which implies that the remaining <jats:italic>k<\/jats:italic>-assignments refer to semi-essential terms of <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\bar{\\chi }}_{W}(x)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:msub>\n                      <mml:mover>\n                        <mml:mrow>\n                          <mml:mi>\u03c7<\/mml:mi>\n                        <\/mml:mrow>\n                        <mml:mrow>\n                          <mml:mo>\u00af<\/mml:mo>\n                        <\/mml:mrow>\n                      <\/mml:mover>\n                      <mml:mi>W<\/mml:mi>\n                    <\/mml:msub>\n                    <mml:mrow>\n                      <mml:mo>(<\/mml:mo>\n                      <mml:mi>x<\/mml:mi>\n                      <mml:mo>)<\/mml:mo>\n                    <\/mml:mrow>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula>. This property enables us to efficiently compute in time <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\mathcal {O}}(n^2)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>O<\/mml:mi>\n                    <mml:mo>(<\/mml:mo>\n                    <mml:msup>\n                      <mml:mi>n<\/mml:mi>\n                      <mml:mn>2<\/mml:mn>\n                    <\/mml:msup>\n                    <mml:mo>)<\/mml:mo>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> all the remaining <jats:italic>k<\/jats:italic>-assignments out of the already computed essential <jats:italic>k<\/jats:italic>-assignments. It follows that time complexity for computing the sequence of all <jats:italic>k<\/jats:italic>-cardinality assignments is <jats:inline-formula><jats:alternatives><jats:tex-math>$${\\mathcal {O}}(n^3)$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mi>O<\/mml:mi>\n                    <mml:mo>(<\/mml:mo>\n                    <mml:msup>\n                      <mml:mi>n<\/mml:mi>\n                      <mml:mn>3<\/mml:mn>\n                    <\/mml:msup>\n                    <mml:mo>)<\/mml:mo>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula>, which is the best known time for this problem.  \n<\/jats:p>","DOI":"10.1007\/s10878-022-00889-4","type":"journal-article","created":{"date-parts":[[2022,7,24]],"date-time":"2022-07-24T17:02:15Z","timestamp":1658682135000},"page":"1265-1283","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Computing the sequence of k-cardinality assignments"],"prefix":"10.1007","volume":"44","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0255-0885","authenticated-orcid":false,"given":"Amnon","family":"Rosenmann","sequence":"first","affiliation":[]}],"member":"297","published-online":{"date-parts":[[2022,7,24]]},"reference":[{"key":"889_CR1","unstructured":"Ahuja RK, Magnanti TL, Orlin JB (1993) Network flows (Prentice Hall, Inc., Englewood Cliffs, NJ), pp. xvi+846. 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