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Discussion
Over coffee, Bob said that he really liked this chapter. This material was full of cases of very concrete procedures for doing useful things. I like that.
Discussion
Over coffee, Bob said that he really liked this chapter. This material was full of cases of very concrete procedures for doing useful things. I like that. Yolanda offered a somewhat different perspective On the other hand, this last procedure only seems to work with interval orders and we still don't have a clue as to how to find the width of a poset in the general case. This might be very difficultlike the graph coloring problems discussed in the last chapter. Dave weighed in with Somehow I think there's going to be a fairly efficient process that works for all posets. We may not have all the tools yet, but let's wait a bit.
Not much was said for a while and after a pause, Carlos ventured that there were probably a lot of combinatorial problems for posets that had analogous versions for graphs and in those cases, the poset version would be a bit more complicated, sometime a little bit and sometimes a very big bit. Zori was quiet but she was thinking. These poset structures might even be useful, as she could imagine many settings in which a linear order was impossible or impractical. Maybe there were ways here to earn a few dollars.
Ҳоло шумо Ҳеҷ ҳисобкунак инро ҳал намекунад, лекин қисмҳои он ҳисобшавандаанд. Яке аз инҳоро дар поён санҷед ё худи худро ворид кунед.
Дар ҳисоби ройгон ба ҳар як дарс қайдҳо илова карда мешаванд, қайди он, ки шумо чӣ кор кардаед, масъалаҳои ҳалшуда дар як ҷо ва муаллиме, ки шумо метавонед дар бораи ин саҳифа пурсед. Математика барои ҳама кушода аст, хоҳ ворид шуда бошад ё на.
Бақайдгирӣ Ворид шуданСимволы, используемые здесь
Барои муайянкунии пурраи маъно, тасвир ва маънои ҳар як ҳарф дар он, ба ҳар як аломат пахш кунед.
Саволҳои маъмул
Permutation or combination?
Ask whether order matters. A lock code is a permutation (order matters); a hand of cards is a combination (it does not).
What is a graph in this sense?
Dots (vertices) joined by lines (edges), not a plot. Road maps, social networks and molecules are graphs; questions like "is there a route" and "how few colours" are graph theory.
Қисми ин саҳифа аз Keller & Trotter, Applied Combinatorics (CC BY-SA 4.0). Дар ин ҷо барои мо чизе нест, ки мо ба он бирасем.
& Иловаи забон Combinatorics & Graph Theory
The counting principlesPigeonhole principle and inclusion, exclusionBinomial coefficients and Pascal's triangleRecurrences and generating functionsGraphs: vertices, edges, degreesPaths, cycles, trees, Euler and HamiltonColouring and planar graphs