added 2015/day11

Author: anight

2015/day11/answers.txt

@@ -0,0 +1,2 @@
+cqjxxyzz
+cqkaabcc

2015/day11/input.txt

@@ -0,0 +1 @@
+cqjxjnds

2015/day11/run.py

@@ -0,0 +1,56 @@
+#! /usr/bin/env python3
+
+def load_data(filename):
+	with open(filename, 'r') as f:
+		for line in f:
+			line = line.rstrip('\n')
+			yield line
+
+password = next(load_data('input.txt'))
+
+# Part One
+
+def next_valid_after(password):
+	def next_after(password, i=-1):
+		a = chr(ord(password[i]) + 1)
+		carry = False
+		if a in 'iol':
+			a = chr(ord(a) + 1)
+		elif a == chr(ord('z') + 1):
+			a = 'a'
+			carry = True
+		password = password[:i] + a + password[len(password)+i+1:len(password)]
+		if carry:
+			return next_after(password, i-1)
+		return password
+	def valid(password):
+		if 'i' in password or 'o' in password or 'l' in password:
+			return False
+		pairs = []
+		straight3 = False
+		for i in range(1, len(password)):
+			if password[i] == password[i-1] and len(pairs) < 2:
+				if not pairs:
+					pairs.append(i-1)
+				elif password[pairs[0]] != password[i]:
+					pairs.append(i-1)
+			elif ord(password[i]) == ord(password[i-1]) + 1:
+				if i > 1 and ord(password[i-1]) == ord(password[i-2]) + 1:
+					straight3 = True
+		return len(pairs) == 2 and straight3
+	while password != 'z' * len(password):
+		password = next_after(password)
+		if valid(password):
+			return password
+	raise Exception("Not found")
+
+result = next_valid_after(password)
+
+print(result)
+
+# Part Two
+
+result = next_valid_after(result)
+
+print(result)
+

README.md

@@ -1,6 +1,6 @@
 ```
       1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
-2015 ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- -- -- -- -- -- -- -- -- -- -- -- -- -- +
+2015 ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- -- -- -- -- -- -- -- -- -- -- -- -- +
 2016 ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -
 2017 ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -
 2018 ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- -- -- -- -- -- -- -- -- -- -- -- -- -- +