// Submit without any data to run with the challenge // data. Otherwise, put the target distance on the // first line, the first person's name, walking // speed, & biking speed on the second line, and the // second person's name, walking speed, & biking // speed on the third line. // Created for this challenge: // https://www.sololearn.com/post/32445 // CHALLENGE TIME // write a code for this word problem // Xavier and Yves have to cover 20 km. They should // start together and have to arrive at their // destination at the same time. They have a single // bike that they take turns riding. Each time a // driver dismounts, he leaves the bicycle by the // side of the road and walk on, while the other man // finally arrives at the bike and jumps on it. // Xavier walks at 4km / h and rides at 10km / h, // Yves walks at 5km / h and rides at 8km / h. // Suppose that both men walk or cycle at these // speeds and never stop restoring their journey? // put you codes and questions in the comments // Data class to hold the person's name and // distances. It starts as K/H and is converted to // mm/H. data class Stats(val name: String, var walks: Long, var bikes: Long) // Data class to hold a time period. The time is in // tenths of a second. It also has the millimeters // each person travels during that time. data class Time(var time: Int, var first: Long, var second: Long) // Extend the Int class to provide a time string in // hours, minutes, seconds, and tenths of seconds. fun Int.time() = "%2d:%02d:%02d.%d".format(this/36000, this%36000/600, this%600/10, this%10) // Extend the Long class to display the number with // commas so a millimeter value show the meters and // kilometers. fun Long.comma() = when { this < 1000L -> "%10d".format(this) this < 1000000L -> "%6d,%03d".format(this/1000L, this%1000L) else -> "%2d,%03d,%03d".format(this/1000000L, this/1000L%1000L, this%1000L) } // when // Extend the Iterable class to add a sum to process // Long values. inline fun Iterable.sumByLong( selector: (T) -> Long): Long { return map {selector(it)}.sum() } // sumByLong // Process the data to figure out the results. fun process(distance: Long, people: List) { // Convert the kilometers into millimeters. val millimeters = distance*1000000L // List of the three time periods for: first person // biking & second person walking, both people // walking so the second person can get to the // bike, and first person walking to the // destination & the second biking there. Each // period has it's length and distance travel for // each person. val results = List(3) {Time(0, 0L, 0L)} // Convert K/H to millimeters/hour for the people. fun convert() { for (person in people) { person.walks *= 1000000L person.bikes *= 1000000L } // for } // convert // Display the final table. fun display() { // Declare and initialize the summation of travel // time & distance. Declare and initialize the // travel speed of first person for the three // time periods followed by the second person. val sum = Time(results.sumBy {it.time}, results.sumByLong {it.first}, results.sumByLong {it.second}) val speed = listOf("Bike", "Walk", "Walk", "Walk", "Walk", "Bike") // Print the heading. print(" %12s".format(people[0].name)) println("%17s".format(people[1].name)) // For each of the time periods, print it. for (index in 0..2) { print(results[index].time.time()) print(" ${speed[index]}") print(" ${results[index].first.comma()}") print(" ${speed[index+3]}") println(" ${results[index].second.comma()}") } // for // Print the totals for the three time periods. print(sum.time.time()) print(" ${sum.first.comma()}") println(" ${sum.second.comma()}") } // display // Figure out the results in millimeters/tenth of // a second. fun setup() { // Calculate the average time needed for both // to cover half the distance by bike. Figure // out how far they actually got with the // first person biking and the second walking. results[0].time = (millimeters*36000L/ (people[0].bikes+people[1].bikes)).toInt() results[0].first = results[0].time.toLong()* people[0].bikes/36000L results[0].second = results[0].time.toLong()* people[1].walks/36000L // Figure out how long it takes for the second // person to reach the bike. Calculate how far // they both get walking for this length of time. results[1].time = ((results[0].first- results[0].second)*36000L/ people[1].walks).toInt() results[1].first = results[1].time.toLong()* people[0].walks/36000L results[1].second = results[1].time.toLong()* people[1].walks/36000L // Use the first time calculated for this // period and figure out how far they actually // got with the first person walking and the // second one biking. results[2].time = results[0].time results[2].first = results[2].time.toLong()* people[0].walks/36000L results[2].second = results[2].time.toLong()* people[1].bikes/36000L } // setup // Adjust the time to find best choice. fun adjust() { // Verify the value is okay. fun check(value: Long) = value in millimeters-199..millimeters+199 // Generate the totals and, if either distance // isn't within a reasonable offset from the // target, make some adjustments. var sum = Time(results.sumBy {it.time}, results.sumByLong {it.first}, results.sumByLong {it.second}) if (!check(sum.first) || !check(sum.second)) { // Find out which direction we need to go // and use 16 minutes as our adjustment. // Repeat adjusting, until we get our // reasonable offset. val status = sum.first < sum.second var adjust = if (status) 10000 else -10000 do { // Make our adjustment and recalculate // everything. Figure out how far they // actually got with the first person // biking and the second walking. results[0].time += adjust results[0].first = results[0].time.toLong()* people[0].bikes/36000L results[0].second = results[0].time.toLong()* people[1].walks/36000L // Figure out how long it takes for the // second person to reach the bike. Calculate // how far they both get walking for this // length of time. results[1].time = ((results[0].first- results[0].second)*36000L/ people[1].walks).toInt() results[1].first = results[1].time.toLong()* people[0].walks/36000L results[1].second = results[1].time.toLong()* people[1].walks/36000L // Figure out how long the first person // must walk to get there. Using that time // to figure out how far they actually got // with the first person walking and the // second biking. results[2].time = ((millimeters- results[0].first- results[1].first)*36000L/ people[0].walks).toInt() results[2].first = results[2].time.toLong()* people[0].walks/36000L results[2].second = results[2].time.toLong()* people[1].bikes/36000L // Generate the totals and, if the adjustment // was too much, put it back and try a // smaller amount. sum = Time(results.sumBy {it.time}, results.sumByLong {it.first}, results.sumByLong {it.second}) if ((status && sum.first > sum.second)) { results[0].time -= adjust adjust /= 10 } else if (!status && sum.first < sum.second) { results[0].time -= adjust adjust /= 10 } // if } while (!check(sum.first) || !check(sum.second)) } // if } // adjust // Display the message. println("Time is displayed to a tenth of a second.") println("Distance is displayed in millimeters.") println("We ignore up to a twenty centimeters") println("difference, as the slowest movement of") println("1 kilometer/hour covers that under a") println("second.") println() // Setup and display the results. convert() setup() adjust() display() } // process // Setup to process the challenge. fun main(args: Array) { // Try letting the user pick the data. try { // Read the target distance from the first line, // the first person's name, walking speed, & // biking speed from the second line, and the // second person's name, walking speed, & biking // speed from the third line. val distance = readLine()!!.toLong() val person1 = readLine()!!.split(" ") val person2 = readLine()!!.split(" ") // If either person didn't get 3 values, throw // an exception. if (person1.size != 3 || person2.size != 3) throw IllegalArgumentException( "Incorrect inputs!") // Generate the list possibly generating an // exception. Verify that a solution is // possible or throw an exception. If it is // good, process it. val list = listOf(Stats(person1[0], person1[1].toLong(), person1[2].toLong()), Stats(person2[0], person2[1].toLong(), person2[2].toLong())) if (list[0].bikes < list[1].walks || list[0].walks > list[1].bikes || list[0].walks < 1L || list[1].walks < 1L || distance < 1L) throw IllegalArgumentException( "Incorrect inputs!") process(distance, list) // On exception, complain and use the challenge // values. } catch (error: Throwable) { println("Bad inputs, using defaults!") process(20L, listOf(Stats("Xavier", 4L, 10L), Stats("Yves", 5L, 8L))) } // try } // main

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