// Input: nothing for default cases or an integer // between one and nine. // Created for this challenge: // https://www.sololearn.com/post/136808 // Hexagon Pattern // Given an input of between one and nine, display // a hexagon. One should display three lines and // five columns. Each higher number adds two lines // (one above & below) and four columns (two before // & after.) Each higher number contains all lower // hexagons within it. All numbers on a line have // a space between them. The odd lines have all // numbers in the same column. The even lines have // all numbers lining up under the odd's spaces. // The pattern for one has six number one // characters. The first and third line contain a // space, one, space, one, and optionally space. // The second line is a one, three spaces, and a // one. // The two pattern has 12 twos. The first and fifth // line have two spaces, two, space, two, space, // two, and optionally two spaces. The second and // fourth line have space, two, space, one, space, // one, space, two, and optionally space. The third // line has two, space, one, three spaces, one, and // two. // Pattern for 9: // 9 9 9 9 9 9 9 9 9 9 // 9 8 8 8 8 8 8 8 8 8 9 // 9 8 7 7 7 7 7 7 7 7 8 9 // 9 8 7 6 6 6 6 6 6 6 7 8 9 // 9 8 7 6 5 5 5 5 5 5 6 7 8 9 // 9 8 7 6 5 4 4 4 4 4 5 6 7 8 9 // 9 8 7 6 5 4 3 3 3 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 2 2 2 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 2 2 2 3 4 5 6 7 8 9 // 9 8 7 6 5 4 3 3 3 3 4 5 6 7 8 9 // 9 8 7 6 5 4 4 4 4 4 5 6 7 8 9 // 9 8 7 6 5 5 5 5 5 5 6 7 8 9 // 9 8 7 6 6 6 6 6 6 6 7 8 9 // 9 8 7 7 7 7 7 7 7 7 8 9 // 9 8 8 8 8 8 8 8 8 8 9 // 9 9 9 9 9 9 9 9 9 9 // Method to extend the Int class with an absolute // value. fun Int.abs() = Math.abs(this) // Function to display the digits. A digit only // gets displayed, when the level is greater or // equal to the digit, the line offset is less // or equal to the digit from the center, and // the offset (line offset plus column offset) // is less or equal to the digit times two. // Otherwise, display a space. fun process(level: Int, line: Int, offset: Int) { when { level >= 1 && line <= 1 && offset <= 2 -> print('1') level >= 2 && line <= 2 && offset <= 4 -> print('2') level >= 3 && line <= 3 && offset <= 6 -> print('3') level >= 4 && line <= 4 && offset <= 8 -> print('4') level >= 5 && line <= 5 && offset <= 10 -> print('5') level >= 6 && line <= 6 && offset <= 12 -> print('6') level >= 7 && line <= 7 && offset <= 14 -> print('7') level >= 8 && line <= 8 && offset <= 16 -> print('8') level >= 9 && line <= 9 && offset <= 18 -> print('9') else -> print(' ') } // when } // process // Function to display the hexagon patterns. fun hex(level: Int) { // Find the center of the shape both column and // line. For each line of the shape, process it's // columns. val center = level*2+2 val middle = level+1 for (line in 1..(level*2+1)) { // For each column of the line, figure out and // display it's character. for (column in 1..(level*4+3)) // If this is the center, it must be blank. if (line == middle && column == center) print(' ') // Otherwise, if the line is odd, the column // might get a digit when it's odd or even // state matches the level's. Otherwise, it // gets a space. To process when a digit is // generated, we need the level to prevent // higher digits appearing, the line offset // to prevent lower digits from appearing // in lines they don't belong in, and the // offset from the center to decide where // a digit belongs. else if (line%2 == 1) if (column%2 == level%2) process(level, (line-middle).abs(), (line-middle).abs()+ (column-center).abs()) else print(' ') // Otherwise, the line is even so the column // might get a digit when it's odd or even // state does not matches the level's. // Otherwise, it gets a space. To process // when a digit is generated, we need the // level to prevent higher digits appearing, // the line offset to prevent lower digits // from appearing in lines they don't belong // in, and the offset from the center to // decide where a digit belongs. else if (column%2 != level%2) process(level, (line-middle).abs(), (line-middle).abs()+ (column-center).abs()) else print(' ') // Finish off the display of the line, println() } // for } // hex // Main function for this challenge. fun main(args: Array) { // Try reading the level from the user. Cause an // exception for input that is not an integer // between one and nine. Otherwise, process it. try { val level = readLine()!!.toInt() if (level !in 1..9) throw IllegalArgumentException("Bad input!") hex(level) // On exception, complain and process our test // cases. } catch (error: Throwable) { println("Bad input using defaults!") for (level in listOf(1, 3, 9)) { hex(level) println() } // for } // try } // main

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