examples/rosettacode/zigzag_matrix.nit

   1 #!/usr/bin/env nit
   2 #
   3 # This file is part of NIT ( http://www.nitlanguage.org ).
   4 # This program is public domain
   5 #
   6 # Task: Zig-zag matrix
   7 # SEE: <http://rosettacode.org/wiki/Zig-zag_matrix>
   8
   9 fun zig_zag(number: Int): Array[Array[Int]] do
  10         var first_number = 0
  11         var last_number = number * number - 1
  12         # x: line position
  13         # y: column position
  14         var x = 0
  15         var y = 0
  16         # true: top-right
  17         # false: bottom-left
  18         var trajectory = true
  19         # first array: column
  20         # second array: line
  21         var array = new Array[Array[Int]]
  22         for i in [0..number[ do array.add(new Array[Int].filled_with(0, number))
  23
  24         while first_number <= last_number do
  25                 array[y][x] = first_number
  26                 array[number - y - 1][number - x - 1] = last_number
  27
  28                 first_number += 1
  29                 last_number -= 1
  30
  31                 if x == 0 and y == 0 then
  32                         x += 1
  33                         trajectory = false
  34                 else
  35                         if y == 0 and trajectory then
  36                                 trajectory = false
  37                                 x += 1
  38                                 continue
  39                         end
  40                         if y == 0 and not trajectory then
  41                                 x -= 1
  42                                 y += 1
  43                                 continue
  44                         end
  45                         if x == 0 and not trajectory then
  46                                 trajectory = true
  47                                 y += 1
  48                                 continue
  49                         end
  50                         if x == 0 and trajectory then
  51                                 x += 1
  52                                 y -= 1
  53                                 continue
  54                         end
  55                         if trajectory then
  56                                 x += 1
  57                                 y -= 1
  58                         else
  59                                 x -= 1
  60                                 y += 1
  61                         end
  62                 end
  63         end
  64         return array
  65 end
  66
  67 var number = 10
  68 var number_length_max = (number * number - 1).to_s.length
  69 for line in zig_zag(number) do
  70         for element in line do
  71                 printn element
  72                 var blank = number_length_max - element.to_s.length + 1
  73                 for x in blank.times do printn " "
  74         end
  75         print ""
  76 end