Towers of Hanoi: Difference between revisions

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@@ Line 2,211: / Line 2,211: @@
 =={{header|Ruby}}==
-<lang ruby>def move(num_disks, starting_stick, target_stick, using_stick)
+<lang ruby>def move(num_disks, start=0, target=1, using=2)
   if num_disks == 1
+   @towers[target] << @towers[start].pop
-    target_stick << starting_stick.shift
+    puts "Move disk from #{start} to #{target} : #{@towers}"
-    status
   else
-    move(num_disks-1, starting_stick, using_stick, target_stick)
+    move(num_disks-1, start, using, target)
-    move(1, starting_stick, target_stick, using_stick)
+    move(1,           start, target, using)
-    move(num_disks-1, using_stick, target_stick, starting_stick)
+    move(num_disks-1, using, target, start)
   end
-end</lang>
+end
+n = 5
+@towers = [[*1..n].reverse, [], []]
+move(n)</lang>
+{{out}}
-<lang ruby>
+<pre>
-require 'pp'
+Move disk from 0 to 1 : [[5, 4, 3, 2], [1], []]
-# solve(source, via, target)
+Move disk from 0 to 2 : [[5, 4, 3], [1], [2]]
+Move disk from 1 to 2 : [[5, 4, 3], [], [2, 1]]
+Move disk from 0 to 1 : [[5, 4], [3], [2, 1]]
+Move disk from 2 to 0 : [[5, 4, 1], [3], [2]]
+Move disk from 2 to 1 : [[5, 4, 1], [3, 2], []]
+Move disk from 0 to 1 : [[5, 4], [3, 2, 1], []]
+Move disk from 0 to 2 : [[5], [3, 2, 1], [4]]
+Move disk from 1 to 2 : [[5], [3, 2], [4, 1]]
+Move disk from 1 to 0 : [[5, 2], [3], [4, 1]]
+Move disk from 2 to 0 : [[5, 2, 1], [3], [4]]
+Move disk from 1 to 2 : [[5, 2, 1], [], [4, 3]]
+Move disk from 0 to 1 : [[5, 2], [1], [4, 3]]
+Move disk from 0 to 2 : [[5], [1], [4, 3, 2]]
+Move disk from 1 to 2 : [[5], [], [4, 3, 2, 1]]
+Move disk from 0 to 1 : [[], [5], [4, 3, 2, 1]]
+Move disk from 2 to 0 : [[1], [5], [4, 3, 2]]
+Move disk from 2 to 1 : [[1], [5, 2], [4, 3]]
+Move disk from 0 to 1 : [[], [5, 2, 1], [4, 3]]
+Move disk from 2 to 0 : [[3], [5, 2, 1], [4]]
+Move disk from 1 to 2 : [[3], [5, 2], [4, 1]]
+Move disk from 1 to 0 : [[3, 2], [5], [4, 1]]
+Move disk from 2 to 0 : [[3, 2, 1], [5], [4]]
+Move disk from 2 to 1 : [[3, 2, 1], [5, 4], []]
+Move disk from 0 to 1 : [[3, 2], [5, 4, 1], []]
+Move disk from 0 to 2 : [[3], [5, 4, 1], [2]]
+Move disk from 1 to 2 : [[3], [5, 4], [2, 1]]
+Move disk from 0 to 1 : [[], [5, 4, 3], [2, 1]]
+Move disk from 2 to 0 : [[1], [5, 4, 3], [2]]
+Move disk from 2 to 1 : [[1], [5, 4, 3, 2], []]
+Move disk from 0 to 1 : [[], [5, 4, 3, 2, 1], []]
+</pre>
+or
+<lang ruby># solve(source, via, target)
 # Example:
 # solve([5, 4, 3, 2, 1], [], [])
@@ Line 2,233: / Line 2,270: @@
   disks = towers.inject(0){|sum, tower| sum+tower.length}
   x=0 # sequence number
-  pp towers # initial trace
+  p towers # initial trace
   # have we solved the puzzle yet?
   while towers.last.length < disks do
@@ Line 2,246: / Line 2,283: @@
         # ok, do it!
         towers[to].push(towers[from].pop)
-        pp towers # trace
+        p towers # trace
       end
     end
   end
 end
-</lang>
+solve([5, 4, 3, 2, 1], [], [])</lang>
+{{out}}
+<pre>
+[[5, 4, 3, 2, 1], [], []]
+[[5, 4, 3, 2], [], [1]]
+[[5, 4, 3], [2], [1]]
+[[5, 4, 3], [2, 1], []]
+[[5, 4], [2, 1], [3]]
+[[5, 4, 1], [2], [3]]
+[[5, 4, 1], [], [3, 2]]
+[[5, 4], [], [3, 2, 1]]
+[[5], [4], [3, 2, 1]]
+[[5], [4, 1], [3, 2]]
+[[5, 2], [4, 1], [3]]
+[[5, 2, 1], [4], [3]]
+[[5, 2, 1], [4, 3], []]
+[[5, 2], [4, 3], [1]]
+[[5], [4, 3, 2], [1]]
+[[5], [4, 3, 2, 1], []]
+[[], [4, 3, 2, 1], [5]]
+[[1], [4, 3, 2], [5]]
+[[1], [4, 3], [5, 2]]
+[[], [4, 3], [5, 2, 1]]
+[[3], [4], [5, 2, 1]]
+[[3], [4, 1], [5, 2]]
+[[3, 2], [4, 1], [5]]
+[[3, 2, 1], [4], [5]]
+[[3, 2, 1], [], [5, 4]]
+[[3, 2], [], [5, 4, 1]]
+[[3], [2], [5, 4, 1]]
+[[3], [2, 1], [5, 4]]
+[[], [2, 1], [5, 4, 3]]
+[[1], [2], [5, 4, 3]]
+[[1], [], [5, 4, 3, 2]]
+[[], [], [5, 4, 3, 2, 1]]
+</pre>
 =={{header|Run BASIC}}==
 <lang runbasic>a = move(4, "1", "2", "3")