day16: cleaner code

day16.py

@@ -5,15 +5,15 @@ TEST_SOLUTION_PART1 = 71
 TEST_SOLUTION_PART2 = 7
 
 
-def part1(test_mode=False):
-    my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
-
+def parse_input(to_parse):
     restraints = {}
+    my_ticket = []
     other_tickets = []
 
-    for i, line in enumerate(my_input):
+    for i, line in enumerate(to_parse):
         if not line:
-            other_tickets = my_input[i+5:]
+            my_ticket = list(map(int, to_parse[i+2].split(",")))
+            other_tickets = [list(map(int, ticket.split(","))) for ticket in to_parse[i+5:]]
             break
 
         field, limits = line.split(": ")
@@ -22,94 +22,76 @@ def part1(test_mode=False):
         min_hi, max_hi = limit_hi.split("-")
         restraints[field] = [(int(min_low), int(max_low)), (int(min_hi), int(max_hi))]
 
+    return restraints, my_ticket, other_tickets
+
+
+def is_valid_number(number, restraints):
+    for restraint in restraints.values():
+        if restraint[0][0] <= number <= restraint[0][1] or restraint[1][0] <= number <= restraint[1][1]:
+            return True
+
+    return False
+
+
+def part1(test_mode=False):
+    my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
+    restraints, _, other_tickets = parse_input(my_input)
+
     invalid_numbers = []
     for ticket in other_tickets:
-        for number in ticket.split(","):
-            valid = False
-            number = int(number)
-            for field in restraints:
-                if restraints[field][0][0] <= number <= restraints[field][0][1] or \
-                        restraints[field][1][0] <= number <= restraints[field][1][1]:
-                    valid = True
-
-                    break
-
-            if not valid:
+        for number in ticket:
+            if not is_valid_number(number, restraints):
                 invalid_numbers.append(number)
 
     return sum(invalid_numbers)
 
 
-def part2(test_mode=False):
-    my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
+def get_single_possible_positions(possible_positions):
+    single_possibilities = []
+    while 1:
+        all_done = True
+        for field, possibilities in possible_positions.items():
+            if len(possibilities) == 1:
+                possible_position = possibilities[0]
+                if possible_position not in single_possibilities:
+                    all_done = False
+                    single_possibilities.append(possible_position)
+                    for check_field, check_positions in possible_positions.items():
+                        if possible_position in check_positions and len(check_positions) > 1:
+                            possible_positions[check_field].remove(possible_position)
 
-    restraints = {}
-    possible_positions = {}
-    my_ticket = ''
-    other_tickets = []
-
-    for i, line in enumerate(my_input):
-        if not line:
-            my_ticket = my_input[i+2]
-            other_tickets = my_input[i+5:]
+        if all_done:
             break
 
-        field, limits = line.split(": ")
-        limit_low, limit_hi = limits.split(" or ")
-        min_low, max_low = limit_low.split("-")
-        min_hi, max_hi = limit_hi.split("-")
-        restraints[field] = [(int(min_low), int(max_low)), (int(min_hi), int(max_hi))]
+    return possible_positions
+
+
+def part2(test_mode=False):
+    my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
+    restraints, my_ticket, other_tickets = parse_input(my_input)
+    possible_positions = {}
+    num_fields = len(my_ticket)
 
-    num_fields = len(my_ticket.split(','))
     for field in restraints:
-        possible_positions[field] = [x for x in range(num_fields)]
+        possible_positions[field] = list(range(num_fields))
 
     for ticket in other_tickets:
         invalid = False
-        for position, number in enumerate(ticket.split(",")):
-            valid = False
-            number = int(number)
-            for field in restraints:
-                if restraints[field][0][0] <= number <= restraints[field][0][1] or \
-                        restraints[field][1][0] <= number <= restraints[field][1][1]:
-                    valid = True
-
-                    break
-
-            if not valid:
+        for number in ticket:
+            if not is_valid_number(number, restraints):
                 invalid = True
                 break
 
         if invalid:
             continue
 
-        for position, number in enumerate(ticket.split(",")):
-            number = int(number)
-            for field in restraints:
-                if not restraints[field][0][0] <= number <= restraints[field][0][1] and \
-                        not restraints[field][1][0] <= number <= restraints[field][1][1]:
+        for position, number in enumerate(ticket):
+            for field, restraint in restraints.items():
+                if not restraint[0][0] <= number <= restraint[0][1] and not restraint[1][0] <= number <= restraint[1][1]:
                     possible_positions[field].remove(position)
 
-    single_possibilities = []
-    while 1:
-        all_done = True
-        for field, possibilities in possible_positions.items():
-            possible_position = possibilities[0]
-            if len(possibilities) == 1 and possible_position not in single_possibilities:
-                all_done = False
-                single_possibilities.append(possible_position)
-                for check_field in possible_positions:
-                    try:
-                        if len(possible_positions[check_field]) > 1:
-                            possible_positions[check_field].remove(possible_position)
-                    except ValueError:
-                        pass
-
-        if all_done:
-            break
-
+    possible_positions = get_single_possible_positions(possible_positions)
     answer = 1
-    my_ticket = [int(x) for x in my_ticket.split(",")]
     for field in restraints:
         if field.startswith('departure'):
             answer *= my_ticket[possible_positions[field][0]]