Pub Date : 2014-06-20DOI: 10.1142/9789814730617_0002
S. Abramsky
Contextual Semantics: From Quantum Mechanics to Logic, Databases, Constraints, and Complexity
上下文语义:从量子力学到逻辑、数据库、约束和复杂性
{"title":"Contextual Semantics: From Quantum Mechanics to Logic, Databases, Constraints, and Complexity","authors":"S. Abramsky","doi":"10.1142/9789814730617_0002","DOIUrl":"https://doi.org/10.1142/9789814730617_0002","url":null,"abstract":"Contextual Semantics: From Quantum Mechanics to Logic, Databases, Constraints, and Complexity","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"456 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124321147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-04DOI: 10.1201/9781482292244-13
Anja Gruünheid, Donald Kossmann, Besmira Nushi
Most database operations such as sorting, grouping and computing joins are based on comparisons between two values. Traditional algorithms assume that machines do not make mistakes. This assumption holds in traditional computing environments; however, it does not hold in several new emerging computing environments. In this write-up, we argue the need for new resilient algorithms that take into account that the result of a comparison might be wrong. The goal is to design algorithms that have low cost (make few comparisons) yet produce high-quality results in the presence of errors.
{"title":"When is A=B?","authors":"Anja Gruünheid, Donald Kossmann, Besmira Nushi","doi":"10.1201/9781482292244-13","DOIUrl":"https://doi.org/10.1201/9781482292244-13","url":null,"abstract":"Most database operations such as sorting, grouping and computing joins are based on comparisons between two values. Traditional algorithms assume that machines do not make mistakes. This assumption holds in traditional computing environments; however, it does not hold in several new emerging computing environments. In this write-up, we argue the need for new resilient algorithms that take into account that the result of a comparison might be wrong. The goal is to design algorithms that have low cost (make few comparisons) yet produce high-quality results in the presence of errors.","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114943675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Secure computation enables many parties to jointly compute a function of their private inputs. The security requirement is that the input privacy of any honest party is preserved even if other parties participating in the protocol collude or deviate from the protocol. In concurrent and physical attacks, adversarial parties try to break the privacy of honest parties by exploiting the network connection or physical weaknesses of the honest parties’ machine. This article provides an overview of the results for achieving secure computation in presence of concurrent and physical attacks contained in the phD thesis:”Secure Computation under concurrent and physical attacks", with emphasis to the relation of such results with the state of the art.
{"title":"Secure Computation Under Network and Physical Attacks","authors":"Alessandra Scafuro","doi":"10.14273/UNISA-84","DOIUrl":"https://doi.org/10.14273/UNISA-84","url":null,"abstract":"Secure computation enables many parties to jointly compute a function of their private inputs. The security requirement is that the input privacy of any honest party is preserved even if other parties participating in the protocol collude or deviate from the protocol. In concurrent and physical attacks, adversarial parties try to break the privacy of honest parties by exploiting the network connection or physical weaknesses of the honest parties’ machine. This article provides an overview of the results for achieving secure computation in presence of concurrent and physical attacks contained in the phD thesis:”Secure Computation under concurrent and physical attacks\", with emphasis to the relation of such results with the state of the art.","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125303433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new book by Dr David Manlove of the School of Computing Science has recently been published by World Scientific as part of their Series on Theoretical Computer Science. This book, called “Algorithmics of Matching Under Preferences”, deals with algorithms and complexity issues surrounding the matching of agents to one another when preferences are involved. For example, in several countries, centralised matching schemes handle the annual allocation of intending junior doctors to hospitals based on their preferences over one another. Efficient algorithms required to solve the underlying theoretical matching problems. Similar examples arise in the allocation of pupils to schools, students to projects, kidney patients to donors, and so on. The book surveys algorithmic results for a range of matching problems involving preferences, with practical applications areas including those mentioned above. It covers the classical Stable Marriage, Hospitals/Residents and Stable Roommates problems, where so-called stable matchings are sought, thereby providing an update to “The Stable Marriage problem, Structure and Algorithms”, by Dan Gusfield and Rob Irving, published by MIT Press in 1989. It also extends the coverage to the House Allocation problem, where stability is no longer the key requirement for a matching, and other definitions of optimality hold. This book builds on the author’s prior research in this area, and also his practical experience of developing, with colleagues including Rob Irving and Gregg O’Malley, algorithms for matching kidney patients to donors in the UK (collaborating with NHS Blood and Transplant), for assigning medical students to hospitals in Scotland (in collaboration with NHS Education for Scotland), and for allocating students to elective courses and projects (within the Schools of Medicine and Computing Science at the University of Glasgow, respectively). The book is also timely, as the research area recently came to the forefront in 2012 following the award of the Nobel Prize in Economic Sciences to Alvin Roth and Lloyd Shapley, two leading contributors to the field of matching theory and its application in practical settings, whose work is described in detail throughout the book. A Foreword is contributed by Kurt Mehlhorn of Max-Planck Institut fur Informatik, Saarbrucken, who wrote: “This book covers the research area in its full breadth and beauty. Written by one of the foremost experts in the area, it is a timely update to “The Stable Marriage Problem: Structure and Algorithms” (D. Gusfield and R.W. Irving, 1989). This book will be required reading for anybody working on the subject; it has a good chance of becoming a classic.”
{"title":"Algorithmics of Matching Under Preferences","authors":"D. Manlove","doi":"10.1142/8591","DOIUrl":"https://doi.org/10.1142/8591","url":null,"abstract":"A new book by Dr David Manlove of the School of Computing Science has recently been published by World Scientific as part of their Series on Theoretical Computer Science. This book, called “Algorithmics of Matching Under Preferences”, deals with algorithms and complexity issues surrounding the matching of agents to one another when preferences are involved. \u0000 \u0000For example, in several countries, centralised matching schemes handle the annual allocation of intending junior doctors to hospitals based on their preferences over one another. Efficient algorithms required to solve the underlying theoretical matching problems. Similar examples arise in the allocation of pupils to schools, students to projects, kidney patients to donors, and so on. \u0000 \u0000The book surveys algorithmic results for a range of matching problems involving preferences, with practical applications areas including those mentioned above. It covers the classical Stable Marriage, Hospitals/Residents and Stable Roommates problems, where so-called stable matchings are sought, thereby providing an update to “The Stable Marriage problem, Structure and Algorithms”, by Dan Gusfield and Rob Irving, published by MIT Press in 1989. It also extends the coverage to the House Allocation problem, where stability is no longer the key requirement for a matching, and other definitions of optimality hold. \u0000 \u0000This book builds on the author’s prior research in this area, and also his practical experience of developing, with colleagues including Rob Irving and Gregg O’Malley, algorithms for matching kidney patients to donors in the UK (collaborating with NHS Blood and Transplant), for assigning medical students to hospitals in Scotland (in collaboration with NHS Education for Scotland), and for allocating students to elective courses and projects (within the Schools of Medicine and Computing Science at the University of Glasgow, respectively). \u0000 \u0000The book is also timely, as the research area recently came to the forefront in 2012 following the award of the Nobel Prize in Economic Sciences to Alvin Roth and Lloyd Shapley, two leading contributors to the field of matching theory and its application in practical settings, whose work is described in detail throughout the book. \u0000 \u0000A Foreword is contributed by Kurt Mehlhorn of Max-Planck Institut fur Informatik, Saarbrucken, who wrote: “This book covers the research area in its full breadth and beauty. Written by one of the foremost experts in the area, it is a timely update to “The Stable Marriage Problem: Structure and Algorithms” (D. Gusfield and R.W. Irving, 1989). This book will be required reading for anybody working on the subject; it has a good chance of becoming a classic.”","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128957734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mihai Pǎtraşcu, aged 29, passed away on Tuesday June 5, 2012, after a 1.5 year battle with brain cancer. Mihai’s academic career was short but explosive, full of rich and beautiful ideas as witnessed, e.g., in his 20 STOC/FOCS papers. His many interesting papers are available online at: http://people.csail.mit.edu/mip/papers/index.html. Mihai’s talent showed early. In high school he received numerous medals at national (Romanian) and international olympiads including prizes in informatics, physics and applied math. He received gold medals at the International Olympiad in Informatics (IOI) in both 2000 and 2001. He remained involved with olympiads and was elected member of the International Scientific Committee for the International Olympiad of Informatics since 2010. Mihai’s main research area was data structure lower bounds. In data structures we try to understand how we can efficiently represent, access, and update information. Mihai revolutionized and revitalized the lower bound side, in many cases matching known upper bounds. The lower bounds were proved in the powerful cell-probe model that only charges for memory access, hence which captures both RAM and external memory. Already in 2004 [17], as a second year undergraduate student, with his supervisor Erik Demaine as non-alphabetic second author, he broke the Ω(log n/ log log n) lower bound barrier that had impeded dynamic lower bounds since 1989 [6], and showed the first logarithmic lower bound by an elegant short proof, a true combinatorial gem. The important conclusion was that binary search trees are optimal algorithms for the textbook problem of maintaining prefix sums in a dynamic array. They also proved an Ω(log n) lower bound for dynamic trees, matching Sleator and Tarjan’s upper bound from 1983 [20]. In 2005 he received from the Computing Research Association (CRA) the Outstanding Undergraduate Award for best undergraduate research in the US and Canada. I was myself lucky enough to meet Mihai in 2004, starting one of most intense collaborations I have experienced in my career. It took us almost two years to find the first separation between near-linear and polynomial space in data structures [19]. What kept us going on this hard problem was that we always had lots of fun on the side: playing squash, going on long hikes, and having beers celebrating every potentially useful idea we found on the way. A strong friendship was formed. Mihai published more than 10 papers while pursuing his undergraduate studies at MIT from 2002 to 2006. Nevertheless he finished with a perfect 5.0/5.0 GPA. Over the next 2 years, he did his PhD at MIT. His thesis “Lower Bound Techniques for Data Structures” [11] is a must-read for researchers who want to get into data structure lower bounds. During Mihai’s PhD, I got to be his mentor at AT&T, and in 2009, after a year as Raviv Postdoctoral Fellow at IBM Almaden, he joined me at AT&T. We continued our work on lower bounds, but I also managed to get him inte
米海Pǎtraşcu, 29岁，在与脑癌斗争了一年半后，于2012年6月5日星期二去世。米海的学术生涯短暂而富有爆发力，在他的20篇STOC/FOCS论文中，我们可以看到他充满了丰富而美丽的思想。他的许多有趣的论文都可以在网上找到:http://people.csail.mit.edu/mip/papers/index.html。米海的天赋很早就显露出来了。高中时，他在国家(罗马尼亚)和国际奥林匹克竞赛中获得了许多奖牌，包括信息学、物理学和应用数学方面的奖项。他在2000年和2001年两次获得国际信息学奥林匹克(IOI)金牌。他一直参与奥林匹克运动，并自2010年以来当选为国际信息学奥林匹克国际科学委员会成员。米海的主要研究领域是数据结构下界。在数据结构中，我们试图理解如何有效地表示、访问和更新信息。米海革新和振兴了下界，在许多情况下与已知的上界相匹配。在强大的细胞探针模型中证明了下界，该模型仅对内存访问收费，因此可以捕获RAM和外部内存。早在2004年[17]，作为一名大二的本科生，他与他的导师Erik Demaine作为非字母第二作者，打破了自1989年以来阻碍动态下界的Ω(log n/ log log n)下界屏障[6]，并通过一个优雅的短证明展示了第一个对数下界，一个真正的组合瑰石。重要的结论是，二叉搜索树是教科书中维护动态数组中前缀和问题的最佳算法。他们还证明了动态树的Ω(log n)下界，与1983年Sleator和Tarjan的上界相匹配[20]。2005年，他获得了计算机研究协会(CRA)颁发的美国和加拿大最佳本科研究杰出本科生奖。我自己也很幸运在2004年遇到了Mihai，开始了我职业生涯中最激烈的合作之一。我们花了近两年的时间才在数据结构中首次发现近线性空间和多项式空间的分离[19]。让我们继续解决这个难题的是，我们总是有很多乐趣:打壁球，长途徒步旅行，喝啤酒庆祝我们在路上发现的每一个潜在的有用想法。一段深厚的友谊就此形成。2002年至2006年，米海在麻省理工学院攻读本科期间发表了10多篇论文。尽管如此，他还是以5.0/5.0的GPA成绩完成了学业。在接下来的两年里，他在麻省理工学院获得了博士学位。他的论文《Lower Bound Techniques for Data Structures》[11]是想要进入数据结构下界的研究人员的必读论文。在米哈伊攻读博士学位期间，我成为了他在AT&T的导师。2009年，在IBM阿尔马登做了一年的拉维夫博士后之后，他加入了我在AT&T的工作。我们继续研究下界，但我也设法让他对散列感兴趣，这对实际计算非常重要。我们寻求既实用又理论上强大的方案[15]。
{"title":"Mihai Pǎtraşcu: obituary and open problems","authors":"M. Thorup","doi":"10.1145/2447712.2447737","DOIUrl":"https://doi.org/10.1145/2447712.2447737","url":null,"abstract":"Mihai Pǎtraşcu, aged 29, passed away on Tuesday June 5, 2012, after a 1.5 year battle with brain cancer. Mihai’s academic career was short but explosive, full of rich and beautiful ideas as witnessed, e.g., in his 20 STOC/FOCS papers. His many interesting papers are available online at: http://people.csail.mit.edu/mip/papers/index.html. Mihai’s talent showed early. In high school he received numerous medals at national (Romanian) and international olympiads including prizes in informatics, physics and applied math. He received gold medals at the International Olympiad in Informatics (IOI) in both 2000 and 2001. He remained involved with olympiads and was elected member of the International Scientific Committee for the International Olympiad of Informatics since 2010. Mihai’s main research area was data structure lower bounds. In data structures we try to understand how we can efficiently represent, access, and update information. Mihai revolutionized and revitalized the lower bound side, in many cases matching known upper bounds. The lower bounds were proved in the powerful cell-probe model that only charges for memory access, hence which captures both RAM and external memory. Already in 2004 [17], as a second year undergraduate student, with his supervisor Erik Demaine as non-alphabetic second author, he broke the Ω(log n/ log log n) lower bound barrier that had impeded dynamic lower bounds since 1989 [6], and showed the first logarithmic lower bound by an elegant short proof, a true combinatorial gem. The important conclusion was that binary search trees are optimal algorithms for the textbook problem of maintaining prefix sums in a dynamic array. They also proved an Ω(log n) lower bound for dynamic trees, matching Sleator and Tarjan’s upper bound from 1983 [20]. In 2005 he received from the Computing Research Association (CRA) the Outstanding Undergraduate Award for best undergraduate research in the US and Canada. I was myself lucky enough to meet Mihai in 2004, starting one of most intense collaborations I have experienced in my career. It took us almost two years to find the first separation between near-linear and polynomial space in data structures [19]. What kept us going on this hard problem was that we always had lots of fun on the side: playing squash, going on long hikes, and having beers celebrating every potentially useful idea we found on the way. A strong friendship was formed. Mihai published more than 10 papers while pursuing his undergraduate studies at MIT from 2002 to 2006. Nevertheless he finished with a perfect 5.0/5.0 GPA. Over the next 2 years, he did his PhD at MIT. His thesis “Lower Bound Techniques for Data Structures” [11] is a must-read for researchers who want to get into data structure lower bounds. During Mihai’s PhD, I got to be his mentor at AT&T, and in 2009, after a year as Raviv Postdoctoral Fellow at IBM Almaden, he joined me at AT&T. We continued our work on lower bounds, but I also managed to get him inte","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125047978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-06DOI: 10.1007/978-3-642-24508-4
S. Jukna
{"title":"Boolean Function Complexity Advances and Frontiers","authors":"S. Jukna","doi":"10.1007/978-3-642-24508-4","DOIUrl":"https://doi.org/10.1007/978-3-642-24508-4","url":null,"abstract":"","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128932694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Boolean Satisfiability (SAT) decision problem can be deservedly declared a success story of computer science. Although SAT was the first problem to be proved NP-complete, the last decade and a half have seen dramatic improvements in the performance of SAT solvers on many practical problem instances. These performance improvements enabled a wide range of real-world applications, several of which have key industrial significance. This article surveys the organization of modern conflict-driven clause learning (CDCL) SAT solvers, focusing on the principal techniques that have contributed to this impressive performance. The article also empirically evaluates these techniques on a comprehensive suite of problem instances taken from a range of representative applications, allowing for a better understanding of their relative contribution.
{"title":"Anatomy and Empirical Evaluation of Modern SAT Solvers","authors":"K. Sakallah, Joao Marques-Silva","doi":"10.14288/1.0043924","DOIUrl":"https://doi.org/10.14288/1.0043924","url":null,"abstract":"The Boolean Satisfiability (SAT) decision problem can be deservedly declared a success story of computer science. Although SAT was the first problem to be proved NP-complete, the last decade and a half have seen dramatic improvements in the performance of SAT solvers on many practical problem instances. These performance improvements enabled a wide range of real-world applications, several of which have key industrial significance. This article surveys the organization of modern conflict-driven clause learning (CDCL) SAT solvers, focusing on the principal techniques that have contributed to this impressive performance. The article also empirically evaluates these techniques on a comprehensive suite of problem instances taken from a range of representative applications, allowing for a better understanding of their relative contribution.","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134413562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-30DOI: 10.1007/978-3-642-13962-8_40
Y. Sakakibara
{"title":"Development of a Bacteria Computer: From in silico Finite Automata to in virto AND in vivo","authors":"Y. Sakakibara","doi":"10.1007/978-3-642-13962-8_40","DOIUrl":"https://doi.org/10.1007/978-3-642-13962-8_40","url":null,"abstract":"","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132306793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-02-12DOI: 10.7146/BRICS.V14I5.21928
L. Aceto, Silvio Capobianco
We study Basic Process Algebra with interrupt modulo complete trace equivalence. We show that, unlike in the setting of the more demanding bisimilarity, a ground complete finite axiomatization exists. We explicitly give such an axiomatization, and extend it to a finite complete one in the special case when a single action is present.
{"title":"On the Existence of a Finite Base for Complete Trace Equivalence over BPA with Interrupt","authors":"L. Aceto, Silvio Capobianco","doi":"10.7146/BRICS.V14I5.21928","DOIUrl":"https://doi.org/10.7146/BRICS.V14I5.21928","url":null,"abstract":"We study Basic Process Algebra with interrupt modulo complete trace equivalence. We show that, unlike in the setting of the more demanding bisimilarity, a ground complete finite axiomatization exists. We explicitly give such an axiomatization, and extend it to a finite complete one in the special case when a single action is present.","PeriodicalId":388781,"journal":{"name":"Bull. EATCS","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127635260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：