Problem A（文献资料）A Careful Approach.pdf_大学文库

2009 World Finals hosted by KTH CPC 2009 ou acm progratmimilg牌IM|m Problem a A Careful Approach Input: approach If you think participating in a programming contest is stressful, imagine being an air traffic controller. With human lives at stake, an air traffic controller has to focus on tasks while working under constantly changing conditions as well as dealing with unforeseen events Consider the task of scheduling the airplanes that are landing at an airport. Incoming airplanes report their positions, directions, and speeds, and then the controller has to devise a landing schedule that brings all airplanes safely to the ground. Generally, the more time there is between successive landings, the""safer"a landing schedule is. This extra time gives pilots the opportunity to react to changing weather and other surprises Luckily, part of this scheduling task can be automated -this is where you come in. You will be given scenarios of airplane landings. Each airplane has a time window during which it can safely land. You must compute an order for landing all airplanes that respects these time windows. Furthermore, the airplane landings should be stretched out as much as possible so that the minimum time gap between successive landings is as large as possible. For example, if three airplanes land at 10: 00am, 10: 05am, and 10: 15am, then the smallest gap is five minutes, which occurs between the first two airplanes. Not all gaps have to be the same, but the smallest gap hould be as large as possible The input file contains several test cases consisting of descriptions of landing scenarios. Each test case starts with a line containing a single integer n(2<ns8), which is the number of airplanes in the scenario. This is followed by n lines, each containing two integers a, bi, which give the beginning and end of the closed interval [ai, bi] during which the i plane can land safely. The numbers a; and b, are specified in minutes and satisfy 0≤a1≤b≤1440 The input is terminated with a line containing the single integer zero Outpul For each test case in the input, print its case number(starting with 1)followed by the minimum achievable time gap between successive landings. Print the time split into minutes and seconds, rounded to the closest second Follow the format of the sample output Sample Input Output for the Sample Input Case1:7:30 010 Case2:20:00 1015 010

Problem A A Careful Approach Input: approach.in If you think participating in a programming contest is stressful, imagine being an air traffic controller. With human lives at stake, an air traffic controller has to focus on tasks while working under constantly changing conditions as well as dealing with unforeseen events. Consider the task of scheduling the airplanes that are landing at an airport. Incoming airplanes report their positions, directions, and speeds, and then the controller has to devise a landing schedule that brings all airplanes safely to the ground. Generally, the more time there is between successive landings, the “safer” a landing schedule is. This extra time gives pilots the opportunity to react to changing weather and other surprises. Luckily, part of this scheduling task can be automated – this is where you come in. You will be given scenarios of airplane landings. Each airplane has a time window during which it can safely land. You must compute an order for landing all airplanes that respects these time windows. Furthermore, the airplane landings should be stretched out as much as possible so that the minimum time gap between successive landings is as large as possible. For example, if three airplanes land at 10:00am, 10:05am, and 10:15am, then the smallest gap is five minutes, which occurs between the first two airplanes. Not all gaps have to be the same, but the smallest gap should be as large as possible. Input The input file contains several test cases consisting of descriptions of landing scenarios. Each test case starts with a line containing a single integer n (2 ≤ n ≤ 8), which is the number of airplanes in the scenario. This is followed by n lines, each containing two integers ai, bi, which give the beginning and end of the closed interval [ai, bi] during which the i th plane can land safely. The numbers ai and bi are specified in minutes and satisfy 0 ≤ ai ≤ bi ≤ 1440. The input is terminated with a line containing the single integer zero. Output For each test case in the input, print its case number (starting with 1) followed by the minimum achievable time gap between successive landings. Print the time split into minutes and seconds, rounded to the closest second. Follow the format of the sample output. Sample Input Output for the Sample Input 3 0 10 5 15 10 15 2 0 10 10 20 0 Case 1: 7:30 Case 2: 20:00

2009 World Finals hosted by Kth CPC 2009 以acm International Collegiate Programming Contest Problem b My Bad Input file: bad. in A logic circuit maps its input through various gates to its output with no feedback loops in the circuit. The input and output are an ordered set of logical values, represented here by ones and zeros. The circuits we consider are comprised of and gates(which output I only when their two inputs are both 1), or gates(which output I when one or both of their inputs are 1), exclusive or(xor) gates(which output 1 only when exactly one of the two inputs is 1), and not gates( which output the complement of their single input). The figures below show two Figure 1: Circuit with 2 gates Figure 2: Circuit with 4 gates Unfortunately, real gates sometimes fail. Although the failures may occur in many different ways, this problem limits attention to gates that fail in one of three ways: 1)al ways inverting the correct output, 2)always yielding 0, and 3)always yielding 1. In the circuits for this problem, at most one gate will fail You must write a program that analyzes a circuit and a number of observations of its input and output to see if the circuit is performing correctly or incorrectly. If at least one set of inputs produces the wrong output, your program must also attempt to determine the unique failing gate and the way in which this gate is failing. This may not always be possible Input The input consists of multiple test cases, each representing a circuit with input and output descriptions. Each test case has the following parts in order 1. A line containing three positive integers giving the number of inputs(Ns8), the number of gates(Gs19) nd the number of outputs(Us19)in the 2. One line of input for each gate. The first line describes gate gr. If there are several gates, the next line describes gate g2, and so on. Each of these lines contains the gate type(a=and, n=not, o=or, and x=exclusive or), and identification of the input(s)to the gate. Gate input comes from the circuit inputs (i1, i2,.or the output of another gate(g1, g 2,. 3. A line containing the numbers of the gates connected to the U outputs u, u2,.. For example, if there are three outputs, and uy comes from gs, u2 from gl, and us from ga, then the line would contain: 5 1 4 4. A line containing an integer which is the number of observations of the circuits behavior(B) 5. Finally B lines, each containing N values(ones and zeros) giving the observed input values and U values giving the corresponding observed output values. No two observations have the same input values Consecutive entries on any line of the input are separated by a single space. The input is terminated with a line containing three zeros

Problem B My Bad Input file: bad.in A logic circuit maps its input through various gates to its output with no feedback loops in the circuit. The input and output are an ordered set of logical values, represented here by ones and zeros. The circuits we consider are comprised of and gates (which output 1 only when their two inputs are both 1), or gates (which output 1 when one or both of their inputs are 1), exclusive or (xor) gates (which output 1 only when exactly one of the two inputs is 1), and not gates (which output the complement of their single input). The figures below show two circuits. or not i1 g2 i2 g1 o1 Figure 1: Circuit with 2 gates Figure 2: Circuit with 4 gates Unfortunately, real gates sometimes fail. Although the failures may occur in many different ways, this problem limits attention to gates that fail in one of three ways: 1) always inverting the correct output, 2) always yielding 0, and 3) always yielding 1. In the circuits for this problem, at most one gate will fail. You must write a program that analyzes a circuit and a number of observations of its input and output to see if the circuit is performing correctly or incorrectly. If at least one set of inputs produces the wrong output, your program must also attempt to determine the unique failing gate and the way in which this gate is failing. This may not always be possible. Input The input consists of multiple test cases, each representing a circuit with input and output descriptions. Each test case has the following parts in order. 1. A line containing three positive integers giving the number of inputs (N ≤ 8), the number of gates (G ≤ 19), and the number of outputs (U ≤ 19) in the circuit. 2. One line of input for each gate. The first line describes gate g1. If there are several gates, the next line describes gate g2, and so on. Each of these lines contains the gate type (a = and, n = not, o = or, and x = exclusive or), and identification of the input(s) to the gate. Gate input comes from the circuit inputs (i1, i2, …) or the output of another gate (g1, g2, …). 3. A line containing the numbers of the gates connected to the U outputs u1, u2, …. For example, if there are three outputs, and u1 comes from g5, u2 from g1, and u3 from g4, then the line would contain: 5 1 4 4. A line containing an integer which is the number of observations of the circuit’s behavior (B). 5. Finally B lines, each containing N values (ones and zeros) giving the observed input values and U values giving the corresponding observed output values. No two observations have the same input values. Consecutive entries on any line of the input are separated by a single space. The input is terminated with a line containing three zeros

2009 World Finals hosted by Kth CPC 2009 以acm International Collegiate Programming Contest Problem e Fare and balanced Input fare in landling traffic congestion is a difficult challenge for young urban planners. Millions of drivers, each with different goals and each making independent choices, combine to form a complex system with sometimes predictable, sometimes chaotic behavior. As a devoted civil servant, you have been tasked with optimizing rush hour traffic over collections of roads All the roads lie between a residential area and a downtown business district. In the morning, each person living in the residential area drives a route to the business district. The morning commuter traffic on any particular road travels in only one direction, and no route has cycles(morning drivers do not backtrack) Each road takes a certain time to drive, so some routes are faster than others. Drivers are much more likely to choose the faster routes, leading to congestion on those roads. In order to balance the traffic as much as possible you are to add tolls to some roads so that the perceived"cost" of every route ends up the same. However, to avoid annoying drivers too much, you must not levy a toll on any driver twice, no matter which route he or she Figure 5 shows a collection of five roads that form routes from the residential area(at intersection 1)to the downtown business district(at intersection 4). The driving cost of each road is written in large blue font. The dotted arrows show the three possible routes from 1 to 4. Initially the costs of the routes are 10, 8 and 12. After adding a toll of cost 2 to the road connecting I and 4 and a toll of cost 4 to the road connecting 3 and 4, the cost of each route becomes 12 10+2=12 10+2 5+3+4=12 3+4 z 2) Figure 5: Roads connecting residential area at intersection 1 to business district at intersection 4 You must determine which roads should have tolls and how much each toll should be so that every route from start to finish has the same cost(driving time cost possible toll)and no route contains more than one toll road Additionally, the tolls should be chosen so as to minimize the final cost. In some settings, it might be impossible to impose tolls that satisfy the above conditions Input consists of several test cases. A test case starts with a line containing an integer N(2SN<50000), whicl is the number of road intersections, and r(I srs50000), which is the number of roads. Each of the next R lines contains three integers xh, yi, and c (Isx,ysN,IsCs1000), indicating that morning traffic takes road i from intersection x, to intersection y with a base driving time cost of cp. Intersection I is the starting residential

Problem E Fare and Balanced Input: fare.in Handling traffic congestion is a difficult challenge for young urban planners. Millions of drivers, each with different goals and each making independent choices, combine to form a complex system with sometimes predictable, sometimes chaotic behavior. As a devoted civil servant, you have been tasked with optimizing rushhour traffic over collections of roads. All the roads lie between a residential area and a downtown business district. In the morning, each person living in the residential area drives a route to the business district. The morning commuter traffic on any particular road travels in only one direction, and no route has cycles (morning drivers do not backtrack). Each road takes a certain time to drive, so some routes are faster than others. Drivers are much more likely to choose the faster routes, leading to congestion on those roads. In order to balance the traffic as much as possible, you are to add tolls to some roads so that the perceived “cost” of every route ends up the same. However, to avoid annoying drivers too much, you must not levy a toll on any driver twice, no matter which route he or she takes. Figure 5 shows a collection of five roads that form routes from the residential area (at intersection 1) to the downtown business district (at intersection 4). The driving cost of each road is written in large blue font. The dotted arrows show the three possible routes from 1 to 4. Initially the costs of the routes are 10, 8 and 12. After adding a toll of cost 2 to the road connecting 1 and 4 and a toll of cost 4 to the road connecting 3 and 4, the cost of each route becomes 12. Figure 5: Roads connecting residential area at intersection 1 to business district at intersection 4 You must determine which roads should have tolls and how much each toll should be so that every route from start to finish has the same cost (driving time cost + possible toll) and no route contains more than one toll road. Additionally, the tolls should be chosen so as to minimize the final cost. In some settings, it might be impossible to impose tolls that satisfy the above conditions. Input Input consists of several test cases. A test case starts with a line containing an integer N (2 ≤ N ≤ 50000), which is the number of road intersections, and R (1 ≤ R ≤ 50000), which is the number of roads. Each of the next R lines contains three integers xi, yi, and ci (1 ≤ xi, yi ≤ N, 1 ≤ ci ≤ 1000), indicating that morning traffic takes road i from intersection xi to intersection yi with a base driving time cost of ci. Intersection 1 is the starting residential