Day 5

5/code.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+
+import string
+import sys
+
+def react(code, offset = 0):
+    reacted = False
+    current = None
+    previous = None
+    index = 0
+    for c in code[offset:]:
+        if index < 1:
+            index += 1
+            continue
+        try:
+            current = code[index]
+        except IndexError:
+            break
+        previous = code[index-1]
+        #print("Checking {} & {}".format(previous, current))
+        if previous.upper() == current.upper():
+            if previous != current:
+                #print("{} and {} reacted around index {} ({})".format(previous, current, index, code[index-2:index+2]))
+                reacted = True
+                break
+        index += 1
+    if reacted:
+        #start = index - 10
+        #if start < 0:
+        start = 0
+        return (True, start, code[:index-1] + code[index+1:])
+    else:
+        return (False, index, code)
+
+if __name__ == '__main__':
+    lines = sys.stdin.readlines()
+    # Part 1
+    #for l in lines:
+    #    reacted = True
+    #    code = l.strip()
+    #    index = 0
+    #    iteration = 0
+    #    while reacted:
+    #        (reacted, index, code) = react(code, index)
+    #        #print("{}, {}, iteration {}".format(reacted, index, iteration))
+    #        iteration += 1
+    #    print("Resulting code: '{}' ({} iterations) has {} units".format(code, iteration, len(code)))
+    permutations = {}
+    for l in lines:
+        for character in string.ascii_lowercase:
+            reacted = True
+            code = l.strip()
+            code = code.replace(character, '')
+            code = code.replace(character.upper(), '')
+            index = 0
+            iteration = 0
+            while reacted:
+                (reacted, index, code) = react(code, index)
+                iteration += 1
+            permutations[character] = {
+                'code': code,
+                'size': len(code),
+                'iterations': iteration,
+            }
+        for character in string.ascii_lowercase:
+            print("Option {}{} result in code length {} ({} iterations)".format(
+                character, character.upper(), permutations[character]['size'],
+                permutations[character]['iterations']))