The problem sets are due on Thursdays by 1:24pm in class. They are posted here the Friday before due date.
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Two times during the semester you may hand in your problem set 120 hours later. If you are doing so, please note this on the pset. Otherwise, late homework is not accepted.
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Problem Set 1, due Sept 4: 1 A (i), 1 B, 1 C, 1H from Van Lint and Wilson, A course in Combinatorics, Second edition
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Problem Set 2, due Sept 11: 2 A, 2 B, 2 D (variation on Greedy Algorithm) from Van Lint and Wilson, A course in Combinatorics, Second edition as well as: pick an arbitrary Prufer code of a tree on 11 nodes and show step by step how to obtain the tree from it. 

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Problem Set 3, due Sept 18: Problems 2 and 9 from exercises for Chapter 1 (p. 7, 8) in <a href="http://newcatalog.library.cornell.edu/catalog/8211273">Algebraic combinatorics: walks, trees, tableaux and more</a> and the two problems 
<a href="pset3-441.pdf">here</a>.

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Problem Set 4, due Sept 25: 5, 9a, 12 (extra credit problem), 33a, 38 from exercises after Chapter 1 in   Stanley: <a href="http://newcatalog.library.cornell.edu/catalog/8049198"> Enumerative Combinatorics, volume 1</a>

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Problem Set 5, due Oct 2: 55, 107, 113, 132 from exercises after Chapter 1 in   Stanley: <a href="http://newcatalog.library.cornell.edu/catalog/8049198"> Enumerative Combinatorics, volume 1</a> as well as the problem   <a href="pset5-441.pdf">here</a>.


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Problem Set 6, due Oct 9: 10A, 10G from Van Lint and Wilson, A course in Combinatorics, Second edition as well as the problem   <a href="pset6-441.pdf">here</a>. 

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The practice exam is <a href="prac-exam.pdf">here</a>.  Here are the <a href="4410_prex_soln.pdf">SOLUTIONS</a> to the practice exam. 


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Problem Set 7, due Oct 30: 6A, B, C from Van Lint and Wilson, A course in Combinatorics, Second edition as well as : pick a poset on at least 10 elements, and decompose it into chains in two different ways (say into 3 and 4 chains) - and then use the method we developed in class for drawing the poset of  order ideals for both decompositions. Draw nice pictures, showing how the poset embeds into N^r, where r is the number of chains. 

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Problem Set 8, due Nov 6: 7A, B, C, D from Van Lint and Wilson, A course in Combinatorics, Second edition

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Problem Set 9, due Nov 13: 7E (i),(ii), (iii), 7F and 5A from Van Lint and Wilson, A course in Combinatorics, Second edition

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The practice exam is <a href="prac-exam2.pdf">here</a>.  Here are the <a href="4410_prex_2_soln.pdf">SOLUTIONS</a> to the practice exam.