From c8d7b67888d74f792ff7f9b65af3e388d132b52e Mon Sep 17 00:00:00 2001
From: Marcel Fries <m.fries@eas-solutions.de>
Date: Wed, 4 Dec 2019 13:49:33 +0100
Subject: [PATCH] Day 4 Part 1

---
 {day01 => day-01}/input.txt    |  0
 {day01 => day-01}/main.nim     |  0
 {day02 => day-02}/computer.nim |  0
 {day02 => day-02}/input.txt    |  0
 {day02 => day-02}/main.nim     |  0
 {day03 => day-03}/input.txt    |  0
 {day03 => day-03}/main.nim     |  0
 day-04/solver.nim              | 46 ++++++++++++++++++++++++++++++++++
 8 files changed, 46 insertions(+)
 rename {day01 => day-01}/input.txt (100%)
 rename {day01 => day-01}/main.nim (100%)
 rename {day02 => day-02}/computer.nim (100%)
 rename {day02 => day-02}/input.txt (100%)
 rename {day02 => day-02}/main.nim (100%)
 rename {day03 => day-03}/input.txt (100%)
 rename {day03 => day-03}/main.nim (100%)
 create mode 100644 day-04/solver.nim

diff --git a/day01/input.txt b/day-01/input.txt
similarity index 100%
rename from day01/input.txt
rename to day-01/input.txt
diff --git a/day01/main.nim b/day-01/main.nim
similarity index 100%
rename from day01/main.nim
rename to day-01/main.nim
diff --git a/day02/computer.nim b/day-02/computer.nim
similarity index 100%
rename from day02/computer.nim
rename to day-02/computer.nim
diff --git a/day02/input.txt b/day-02/input.txt
similarity index 100%
rename from day02/input.txt
rename to day-02/input.txt
diff --git a/day02/main.nim b/day-02/main.nim
similarity index 100%
rename from day02/main.nim
rename to day-02/main.nim
diff --git a/day03/input.txt b/day-03/input.txt
similarity index 100%
rename from day03/input.txt
rename to day-03/input.txt
diff --git a/day03/main.nim b/day-03/main.nim
similarity index 100%
rename from day03/main.nim
rename to day-03/main.nim
diff --git a/day-04/solver.nim b/day-04/solver.nim
new file mode 100644
index 0000000..74f41d6
--- /dev/null
+++ b/day-04/solver.nim
@@ -0,0 +1,46 @@
+import math
+
+# The puzzle input
+const
+  inputLow = 171309
+  inputHigh = 643603
+
+iterator digitsLowToHight(number: int): int =
+  var num = number
+  while (num != 0):
+    yield num mod 10
+    num = num.floorDiv(10)
+
+proc hasAdjacentSame(number: int): bool =
+  var previous = int.high
+  for digit in number.digitsLowToHight:
+    if (previous == digit):
+      return true
+    previous = digit
+  return false
+
+proc digitsAscending(number: int): bool =
+  var previous = int.high
+  for digit in number.digitsLowToHight:
+    if previous < digit:
+      return false
+    previous = digit
+  return true
+
+proc noLargerGroups(number: int): bool =
+  discard
+
+proc countCombinations(lower, upper: int): int =
+  ## Count all possible combinations between two bounds
+  for num in lower .. upper:
+    if (num.hasAdjacentSame and num.digitsAscending):
+      result.inc
+
+proc countCombinationsPart2(lower, upper: int): int =
+  ## Count all possible combinations between two bounds
+  for num in lower .. upper:
+    if (num.hasAdjacentSame and num.digitsAscending and num.noLargerGroups):
+      result.inc
+
+echo "Part 1: Number of combinations with in the range  ->  ", countCombinations(inputLow, inputHigh)
+echo "Part 2: Number of combinations with in the range  ->  ", countCombinationsPart2(inputLow, inputHigh)
\ No newline at end of file