Data commit

Task/15-puzzle-solver/Nim/15-puzzle-solver-1.nim

@@ -0,0 +1,140 @@
+# 15 puzzle.
+
+import strformat
+import times
+
+const
+  Nr = [3, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3]
+  Nc = [3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2]
+
+type
+
+  Solver = object
+    n: int
+    np: int
+    n0: array[100, int]
+    n2: array[100, uint64]
+    n3: array[100, char]
+    n4: array[100, int]
+
+  Value = range[0..15]
+
+# Forward definition.
+proc fN(s: var Solver): bool
+
+#---------------------------------------------------------------------------------------------------
+
+proc fI(s: var Solver) =
+
+  let n = s.n
+  let g = (11 - s.n0[n]) * 4
+  let a = s.n2[n] and uint(15 shl g)
+  s.n0[n + 1] = s.n0[n] + 4
+  s.n2[n + 1] = s.n2[n] - a + a shl 16
+  s.n3[n + 1] = 'd'
+  s.n4[n + 1] = s.n4[n] + ord(Nr[a shr g] > s.n0[n] div 4)
+
+#---------------------------------------------------------------------------------------------------
+
+proc fG(s: var Solver) =
+
+  let n = s.n
+  let g = (19 - s.n0[n]) * 4
+  let a = s.n2[n] and uint(15 shl g)
+  s.n0[n + 1] = s.n0[n] - 4
+  s.n2[n + 1] = s.n2[n] - a + a shr 16
+  s.n3[n + 1] = 'u'
+  s.n4[n + 1] = s.n4[n] + ord(Nr[a shr g] < s.n0[n] div 4)
+
+#---------------------------------------------------------------------------------------------------
+
+proc fE(s: var Solver) =
+
+  let n = s.n
+  let g = (14 - s.n0[n]) * 4
+  let a = s.n2[n] and uint(15 shl g)
+  s.n0[n + 1] = s.n0[n] + 1
+  s.n2[n + 1] = s.n2[n] - a + a shl 4
+  s.n3[n + 1] = 'r'
+  s.n4[n + 1] = s.n4[n] + ord(Nc[a shr g] > s.n0[n] mod 4)
+
+#---------------------------------------------------------------------------------------------------
+
+proc fL(s: var Solver) =
+
+  let n = s.n
+  let g = (16 - s.n0[n]) * 4
+  let a = s.n2[n] and uint(15 shl g)
+  s.n0[n + 1] = s.n0[n] - 1
+  s.n2[n + 1] = s.n2[n] - a + a shr 4
+  s.n3[n + 1] = 'l'
+  s.n4[n + 1] = s.n4[n] + ord(Nc[a shr g] < s.n0[n] mod 4)
+
+#---------------------------------------------------------------------------------------------------
+
+proc fY(s: var Solver): bool =
+
+  if s.n2[s.n] == 0x123456789abcdef0'u:
+    return true
+  if s.n4[s.n] <= s.np:
+    return s.fN()
+
+#---------------------------------------------------------------------------------------------------
+
+proc fN(s: var Solver): bool =
+
+  let n = s.n
+  if s.n3[n] != 'u' and s.n0[n] div 4 < 3:
+    s.fI
+    inc s.n
+    if s.fY(): return true
+    dec s.n
+  if s.n3[n] != 'd' and s.n0[n] div 4 > 0:
+    s.fG()
+    inc s.n
+    if s.fY(): return true
+    dec s.n
+  if s.n3[n] != 'l' and s.n0[n] mod 4 < 3:
+    s.fE()
+    inc s.n
+    if s.fY(): return true
+    dec s.n
+  if s.n3[n] != 'r' and s.n0[n] mod 4 > 0:
+    s.fL()
+    inc s.n
+    if s.fY(): return true
+    dec s.n
+
+#---------------------------------------------------------------------------------------------------
+
+proc initSolver(values: array[16, Value]): Solver {.noInit.} =
+
+  result.n = 0
+  result.np = 0
+  result.n0[0] = values.find(0)
+  result.n2[0] = (var tmp = 0'u; for val in values: tmp = tmp shl 4 or uint(val); tmp)
+  result.n4[0] = 0
+
+#---------------------------------------------------------------------------------------------------
+
+proc run(s: var Solver) =
+
+  while not s.fY():
+    inc s.np
+  stdout.write(fmt"Solution found with {s.n} moves: ")
+  for g in 1..s.n:
+    stdout.write(s.n3[g])
+  stdout.write(".\n")
+
+#---------------------------------------------------------------------------------------------------
+
+proc toString(d: Duration): string =
+  # Custom representation of a duration.
+  const Plural: array[bool, string] = ["", "s"]
+  var ms = d.inMilliseconds
+  for (label, d) in {"hour": 3_600_000, "minute": 60_000, "second": 1_000, "millisecond": 1}:
+    let val = ms div d
+    if val > 0:
+      result.add($val & ' ' & label & Plural[val > 1])
+      ms = ms mod d
+      if ms > 0: result.add(' ')

Task/15-puzzle-solver/Nim/15-puzzle-solver-2.nim

@@ -0,0 +1,7 @@
+let start = getTime()
+var solver = initSolver([Value 15, 14,  1,  6,
+                                9, 11,  4, 12,
+                                0, 10,  7,  3,
+                               13,  8,  5,  2])
+solver.run()
+echo fmt"Execution time: {(getTime() - start).toString}."

Task/15-puzzle-solver/Nim/15-puzzle-solver-3.nim

@@ -0,0 +1,7 @@
+let start = getTime()
+var solver = initSolver([Value  0, 12,  9, 13,
+                               15, 11, 10, 14,
+                                3,  7,  2,  5,
+                                4,  8,  6,  1])
+solver.run()
+echo fmt"Execution time: {(getTime() - start).toString}."