{"title":"Fast simulations of the multi-album collector","authors":"D. Barak-Pelleg , D. Berend","doi":"10.1016/j.tcs.2025.115432","DOIUrl":null,"url":null,"abstract":"<div><div>Our starting point is the coupon collector's problem (CCP). In this problem, there are <em>n</em> coupons that are drawn uniformly randomly with replacement. The question is how many drawings on average are needed to collect at least one copy (or some other predetermined number <em>m</em> of copies) of each coupon?</div><div>The problem may be traced back to the 18-th century, having been mentioned already by de Moivre. Numerous questions have been posed based on the problem since its inception, and it turned out to appear naturally in many applications.</div><div>A naive simulation of the process is trivial to implement. However, the runtime of this algorithm makes it impractical for large values of <em>n</em>. We present here an alternative view of the coupon collecting process, for coupons with any probabilities, that allows us to increase the range of <em>n</em>-s (and <em>m</em>-s) for which the simulation may be run. For equi-probable coupons, we present additional improvements, making the simulation possible in a very short time practically for any <em>n</em>. More precisely, we show that the runtime of our algorithm is <span><math><mi>Θ</mi><mo>(</mo><mi>m</mi><mo>+</mo><mi>log</mi><mo></mo><mi>n</mi><mo>)</mo></math></span>.</div><div>We present theoretical results concerning some of the quantities relevant to our algorithms and conduct simulations to test the algorithms in practice.</div></div>","PeriodicalId":49438,"journal":{"name":"Theoretical Computer Science","volume":"1053 ","pages":"Article 115432"},"PeriodicalIF":1.0000,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Theoretical Computer Science","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304397525003706","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"COMPUTER SCIENCE, THEORY & METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
Our starting point is the coupon collector's problem (CCP). In this problem, there are n coupons that are drawn uniformly randomly with replacement. The question is how many drawings on average are needed to collect at least one copy (or some other predetermined number m of copies) of each coupon?
The problem may be traced back to the 18-th century, having been mentioned already by de Moivre. Numerous questions have been posed based on the problem since its inception, and it turned out to appear naturally in many applications.
A naive simulation of the process is trivial to implement. However, the runtime of this algorithm makes it impractical for large values of n. We present here an alternative view of the coupon collecting process, for coupons with any probabilities, that allows us to increase the range of n-s (and m-s) for which the simulation may be run. For equi-probable coupons, we present additional improvements, making the simulation possible in a very short time practically for any n. More precisely, we show that the runtime of our algorithm is .
We present theoretical results concerning some of the quantities relevant to our algorithms and conduct simulations to test the algorithms in practice.
期刊介绍:
Theoretical Computer Science is mathematical and abstract in spirit, but it derives its motivation from practical and everyday computation. Its aim is to understand the nature of computation and, as a consequence of this understanding, provide more efficient methodologies. All papers introducing or studying mathematical, logic and formal concepts and methods are welcome, provided that their motivation is clearly drawn from the field of computing.