Archives of the Vietnam Online Judge - IOI Training main problemset Editors: Ngô Minh Đức Phạm Quang Vũ Sherry Bùi Nguyên Tùng Problem setters of VN_SPOJ My Own Way Kaiel Last updated: 2008-04-02 17:27:50 Preface This electronic material contains a set of algorithmic problems, forming the archives of the Vietnam Online Judge - IOI Training (http://www.spoj.pl/IOITRAIN/), main problemset. The document can be accessed at the following URLs: • in PostScript format: http://www.spoj.pl/IOITRAIN/problems/main.ps • in Portable Document Format: http://www.spoj.pl/IOITRAIN/problems/main.pdf These resources are constantly updated to synchronise with the ever-changing hypertext version of the problems, and to include newly added problems. If you have obtained this document from another source, it is strongly recommended that you should download the current version from one of the aforementioned URLs. Enjoy problem-solving at the Vietnam Online Judge - IOI Training! Disclaimer from the Editors. Despite our best efforts, it is possible that this document contains errors or that some of the content differs slightly from its original hypertext form. We take no responsibility for any such faults and their consequences. We neither authorise nor approve use of this material for any purpose other than facilitating problem solving at the Sphere Online Judge site; nor do we guarantee its fitness for any purpose whatsoever. The layout of the problems in this document is the copyright of the Editors named on the cover (as determined by the appropriate footers in the problem description). The content is the copyright of the respective Editor unless the copyright holder is otherwise stated in the 'resource' section. The document as a whole is not protected by copyright, and fragments of it are to be regarded independently. No responsibility is taken by the Editors if use or redistribution of this document violates either their or third party copyright laws. When referring to or citing the whole or a fragment of this document, please state clearly the aforementioned URLs at which the document is to be found, as well as the resources from which the problems you are referring to originally came. Remarks concerning this document should be sent to the following e-mail address: contact@spoj.pl. Table of Contents 1. Problem NKBUS (2117. Bus) 2. Problem NKTEST (2163. Kiểm tra chương trình) 3. Problem STEEL (2166. Khuôn thép) . problems, forming the archives of the Vietnam Online Judge - IOI Training (http://www.spoj.pl/IOITRAIN/), main problemset. The document can be accessed at. Archives of the Vietnam Online Judge - IOI Training main problemset Editors: Ngô Minh Đức Phạm Quang Vũ Sherry Bùi Nguyên