摘要：The Tamworth TwoBIO '98 - Richard Forster A pair of cows is loose somewhere in the forest. Farmer John is lending his expertise to their capture. Your task is to model their behavior.The chase takes place on a 10 by 10 planar grid. Squares can be empty or they can contain:an obstacle, the cows ( 阅读全文

摘要：Controlling CompaniesSome companies are partial owners of other companies because they have acquired part of their total shares of stock. For example, Ford owns 12% of Mazda. It is said that a company A controls company B if at least one of the following conditions is satisfied:Company A = Company B 阅读全文

摘要：Money SystemsThe cows have not only created their own government but they have chosen to create their own money system. In their own rebellious way, they are curious about values of coinage. Traditionally, coins come in values like 1, 5, 10, 20 or 25, 50, and 100 units, sometimes with a 2 unit coin 阅读全文

摘要：Zero SumConsider the sequence of digits from 1 through N (where N=9) in increasing order:1 2 3 ... N. Now insert either a `+' for addition or a `-' for subtraction or a ` ' [blank] to run the digits together between each pair of digits (not in front of the first digit). Calculate the res 阅读全文

摘要：Longest PrefixIOI'96 The structure of some biological objects is represented by the sequence of their constituents, where each part is denote by an uppercase letter. Biologists are interested in decomposing a long sequence into shorter ones calledprimitives.We say that a sequence S can be compos 阅读全文

摘要：Flip GameTime Limit: 1000MSMemory Limit: 65536KTotal Submissions: 20199Accepted: 8752DescriptionFlip game is played on a rectangular 4x4 field with two-sided pieces placed on each of its 16 squares. One side of each piece is white and the other one is black and each piece is lying either it's bl 阅读全文

摘要：Painter's ProblemTime Limit: 1000MSMemory Limit: 10000KTotal Submissions: 3462Accepted: 1710DescriptionThere is a square wall which is made of n*n small square bricks. Some bricks are white while some bricks are yellow. Bob is a painter and he wants to paint all the bricks yellow. But there is s 阅读全文

摘要：最后1 行，有x4=b4;第3 行： x4+x3=b3,已经求出x4=b4 了，带入第3 行，可求出x3;同理，把x4 x3 带入第2 行，还可求出x2;把x4 x3 x2 带入到第1 行，可求出x1;这就是回带。回带总结：从最后1 行，逐一往回带，从最后1 行代回到第1 行。最关键的时候到了：当无穷多解时，最后几行都是0；没法回带；而某些题目在无穷多解时还要你求最小或最优解，没办法，就得枚举最后行为0 的那几个解；如：1 2 4 3 30 1 3 2 30 0 1 0 20 0 0 0 0可见最后的x4 没法解，如果题中给定x4 的范围，那就枚举x4，然后回带；枚举1 次x4就回带1 次得到 阅读全文

摘要：Party LampsIOI 98 To brighten up the gala dinner of the IOI'98 we have a set of N (10 =0), i.e., 1,4,7,...A counter C records the total number of button presses. When the party starts, all the lamps are ON and the counter C is set to zero. You are given the value of counter C (0 #include #includ 阅读全文