part 2 done

2023/day_11/part 2 solution.py

@@ -1,6 +1,113 @@
-import os
+from queue import Queue
+# import os
 
 with open(r'advent_of_code\2023\day_11\input.txt', 'r') as file:
-    input = file.read()
+    input = file.readlines()
 
-print(input)
+# print(input)
+
+test_input = '''...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....'''
+
+#print(test_input)
+#input = test_input.split('\n')
+
+def expand_universe(input):
+    '''add an extra row or column of empty spaces to each row or column that has no # in it'''
+    print('Expanding universe')
+    # expand empty rows
+    new_input = []
+    empty_rows = []
+    for i, row in enumerate(input):
+        if '#' in row:
+            new_input.append(row)
+        else:
+            new_input.append(row)
+            #new_input.append(row)
+            empty_rows.append(i)
+    
+    # expand empty columns
+    empty_columns = []
+    # Transpose the input
+    transposed_input = list(map(list, zip(*new_input)))
+
+    new_input = []
+    for i, row in enumerate(transposed_input):
+        if '#' in row:
+            new_input.append(row)
+        else:
+            new_input.append(row)
+            #new_input.append(row)
+            empty_columns.append(i)
+
+    # Convert rows back to strings
+    new_input = [''.join(row) for row in new_input]
+    
+    return new_input, empty_rows, empty_columns
+
+def number_galaxies(input):
+    '''gives a unique number to each galaxy(#) in the input grid'''
+    print('Numbering galaxies')
+    # make a copy of the input
+    input_copy = [list(row) for row in input]  # Convert strings to lists
+    # replace the galaxies with their numbers
+    galaxy_coordinates = []  # This list will store the coordinates of each galaxy
+    for i in range(len(input_copy)):
+        for j in range(len(input_copy[i])):
+            if input_copy[i][j] == '#':
+                galaxy_coordinates.append((i, j))  # Store the coordinates of the galaxy
+    # Convert lists back to strings
+    input_copy = [''.join(map(str, row)) for row in input_copy]
+    return input_copy, galaxy_coordinates
+
+def calculate_distance(point1, point2, empty_rows, empty_columns):
+    # Calculate Manhattan distance
+    total_distance = abs(point1[0] - point2[0]) + abs(point1[1] - point2[1])
+    length_to_add = 1000000-1  # The additional length to add when passing through an empty row or column
+
+    # Check each empty row
+    for row in empty_rows:
+        if min(point1[1], point2[1]) <= row <= max(point1[1], point2[1]):
+            total_distance += length_to_add
+
+    # Check each empty column
+    for column in empty_columns:
+        if min(point1[0], point2[0]) <= column <= max(point1[0], point2[0]):
+            total_distance += length_to_add
+
+    return total_distance
+
+
+def find_shortest_path(galaxy_coordinates, empty_rows, empty_columns):
+    # find the shortest path between each pair of galaxies
+    print('Finding the shortest path between each pair of galaxies')
+    galaxy_distances = []
+    for i, point1 in enumerate(galaxy_coordinates):
+        for point2 in galaxy_coordinates[:i]:
+
+            distance = calculate_distance(point1, point2, empty_rows, empty_columns)
+            galaxy_distances.append(distance)
+    return galaxy_distances
+
+def sum_up_distances(galaxy_distances):
+    # sum up all the distances
+    print('Summing up all the distances')
+    total_distance = 0
+    for distance in galaxy_distances:
+        total_distance += distance
+    return total_distance
+
+
+input,empty_rows,empty_columns = expand_universe(input)
+input, galaxy_coordinates = number_galaxies(input)
+galaxy_distances = find_shortest_path(galaxy_coordinates, empty_rows, empty_columns)
+total_distance = sum_up_distances(galaxy_distances)
+print(total_distance)