examples/rosettacode/24_game.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: 24 game
   7 # SEE: <http://rosettacode.org/wiki/24_game>
   8
   9 redef class Char
  10         fun is_op: Bool do return "-+/*".has(self)
  11 end
  12
  13 # Get `numbers` and `operands` from string `operation` collect with `gets` in `main` function
  14 # Fill `numbers` and `operands` array with previous extraction
  15 fun exportation(operation: String, numbers: Array[Int], operands: Array[Char]) do
  16         var previous_char: nullable Char = null
  17         var number: nullable Int = null
  18         var negative = false
  19
  20         for i in operation.length.times do
  21                 var current_char = operation[i]
  22                 var current_int = current_char.to_i
  23
  24                 if (previous_char == null or previous_char.is_op) and current_char == '-' then
  25                         negative = true
  26                         continue
  27                 end
  28
  29                 if current_char.is_digit then
  30                         if number == null then
  31                                 number = current_int
  32                         else
  33                                 number = number * 10 + current_int
  34                         end
  35                 end
  36
  37                 if negative and (current_char.is_op or i == operation.length - 1) then
  38                         number = number - number * 2
  39                         negative = false
  40                 end
  41
  42                 if (current_char.is_op or i == operation.length - 1) and number != null then
  43                         numbers.add(number)
  44                         number = null
  45                 end
  46
  47                 if not negative and current_char.is_op then
  48                         operands.add(current_char)
  49                 end
  50                 previous_char = current_char
  51         end
  52         # Update `numbers` and `operands` array in main function with pointer
  53 end
  54
  55 # Create random numbers between 1 to 9
  56 fun random: Array[Int] do
  57         return [for i in 4.times do 1 + 9.rand]
  58 end
  59
  60 # Make mathematical operation with `numbers` and `operands` and add the operation result into `random_numbers`
  61 fun calculation(random_numbers, numbers: Array[Int], operands: Array[Char]) do
  62         var number = 0
  63         var temp_numbers = numbers.clone
  64
  65         while temp_numbers.length > 1 do
  66                 var operand = operands.shift
  67                 var a = temp_numbers.shift
  68                 var b = temp_numbers.shift
  69
  70                 if operand == '+' then number = a + b
  71                 if operand == '-' then number = a - b
  72                 if operand == '*' then number = a * b
  73                 if operand == '/' then number = a / b
  74
  75                 temp_numbers.unshift(number)
  76         end
  77         if number != 0 then random_numbers.add(number)
  78 end
  79
  80 # Check if used `numbers` exist in the `random_numbers` created
  81 fun numbers_exists(random_numbers, numbers: Array[Int]): Bool do
  82         for number in numbers do
  83                 if not random_numbers.count(number) >= numbers.count(number) then return false
  84         end
  85         return true
  86 end
  87
  88 # Remove `numbers` when they are used
  89 fun remove_numbers(random_numbers, numbers: Array[Int]) do
  90         for number in numbers do random_numbers.remove(number)
  91 end
  92
  93 # Check if the mathematical `operation` is valid
  94 fun check(operation: String): Bool do
  95         var previous_char: nullable Char = null
  96         var next_char: nullable Char = null
  97         var next_1_char: nullable Char = null
  98
  99         for i in operation.length.times do
 100                 var current_char = operation[i]
 101
 102                 if i + 1 < operation.length then
 103                         next_char = operation[i + 1]
 104                         if i + 2 < operation.length then
 105                                 next_1_char = operation[i + 2]
 106                         else
 107                                 next_1_char = null
 108                         end
 109                 else
 110                         next_char = null
 111                 end
 112
 113                 if not current_char.is_op and not current_char.is_digit then return false
 114                 if next_char == null and current_char.is_op then return false
 115
 116                 if previous_char == null  then
 117                         if next_char == null or next_1_char == null then return false
 118                         if current_char == '-' and not next_char.is_digit then return false
 119                         if current_char != '-' and not current_char.is_digit then return false
 120                 else
 121                         if next_char != null then
 122                                 if previous_char.is_digit and current_char.is_op and
 123                                 not (next_char == '-' and next_1_char != null and
 124                                 next_1_char.is_digit or next_char.is_digit) then
 125                                         return false
 126                                 end
 127                         end
 128                 end
 129                 previous_char = current_char
 130         end
 131         return true
 132 end
 133
 134 var random_numbers = new Array[Int]
 135 var operation = ""
 136
 137 random_numbers = random
 138 while not random_numbers.has(24) and random_numbers.length > 1 do
 139         var numbers = new Array[Int]
 140         var operands = new Array[Char]
 141
 142         print "numbers: " + random_numbers.join(", ")
 143         operation = gets
 144         if check(operation) then
 145                 exportation(operation, numbers, operands)
 146                 if numbers_exists(random_numbers, numbers) then
 147                         calculation(random_numbers, numbers, operands)
 148                         remove_numbers(random_numbers, numbers)
 149                 else
 150                         print "NUMBERS ERROR!"
 151                 end
 152         else
 153                 print "STRING ERROR!"
 154         end
 155 end
 156
 157 if random_numbers.has(24) then print "CONGRATULATIONS" else print "YOU LOSE"