Data commit

Task/Esthetic-numbers/Nim/esthetic-numbers.nim

@@ -0,0 +1,82 @@
+import strformat
+
+func isEsthetic(n, b: int64): bool =
+  if n == 0: return false
+  var i = n mod b
+  var n = n div b
+  while n > 0:
+    let j = n mod b
+    if abs(i - j) != 1:
+      return false
+    n = n div b
+    i = j
+  result = true
+
+
+proc listEsths(n1, n2, m1, m2: int64; perLine: int; all: bool) =
+  var esths: seq[int64]
+
+  func dfs(n, m, i: int64) =
+    if i in n..m: esths.add i
+    if i == 0 or i > m: return
+    let d = i mod 10
+    let i1 = i * 10 + d - 1
+    let i2 = i1 + 2
+    case d
+    of 0:
+      dfs(n, m, i2)
+    of 9:
+      dfs(n, m, i1)
+    else:
+      dfs(n, m, i1)
+      dfs(n, m, i2)
+
+  for i in 0..9:
+    dfs(n2, m2, i)
+
+  echo &"Base 10: {esths.len} esthetic numbers between {n1} and {m1}:"
+  if all:
+    for i, esth in esths:
+      stdout.write esth
+      stdout.write if (i + 1) mod perLine == 0: '\n' else: ' '
+    echo()
+  else:
+    for i in 0..<perLine:
+      stdout.write esths[i], ' '
+    echo "\n............"
+    for i in esths.len - perLine .. esths.high:
+      stdout.write esths[i], ' '
+    echo()
+  echo()
+
+
+proc toBase(n, b: int64): string =
+  const Digits = ['0', '1', '2', '3', '4', '5', '6', '7',
+                  '8', '9', 'a', 'b', 'c', 'd', 'e', 'f']
+
+  if n == 0: return "0"
+  var n = n
+  while n > 0:
+    result.add Digits[n mod b]
+    n = n div b
+  for i in 0..<(result.len div 2):
+    swap result[i], result[result.high - i]
+
+
+for b in 2..16:
+  echo &"Base {b}: {4 * b}th to {6 * b}th esthetic numbers:"
+  var n = 1i64
+  var c = 0i64
+  while c < 6 * b:
+    if n.isEsthetic(b):
+      inc c
+      if c >= 4 * b: stdout.write n.toBase(b), ' '
+    inc n
+  echo '\n'
+
+# The following all use the obvious range limitations for the numbers in question.
+listEsths(1000, 1010, 9999, 9898, 16, true)
+listEsths(100_000_000, 101_010_101, 130_000_000, 123_456_789, 9, true)
+listEsths(100_000_000_000, 101_010_101_010, 130_000_000_000, 123_456_789_898, 7, false)
+listEsths(100_000_000_000_000, 101_010_101_010_101, 130_000_000_000, 123_456_789_898_989, 5, false)
+listEsths(100_000_000_000_000_000, 101_010_101_010_101_010, 130_000_000_000_000_000, 123_456_789_898_989_898, 4, false)