2025: improve folder names

2024/04/puzzle1.py

@@ -0,0 +1,115 @@
+import itertools
+
+
+verbose = False
+
+def scan_line(line):
+	to_find = "XMAS"
+	if verbose:
+		if to_find in line:
+			print(line)
+	
+	return line.count(to_find)
+
+def transpose(list_2d):
+	outlist = []
+	for j in range(max(map(len, list_2d))):
+		outlist.append([])
+		for i in range(len(list_2d)):
+			# TODO: This is a weird edge case.
+			if j < len(list_2d[i]):
+				outlist[j].append(list_2d[i][j])
+		outlist[j] = "".join(outlist[j])
+	return outlist
+
+def rotate(list_2d):
+	x_max, y_max = len(list_2d), len(list_2d[0])
+	diagonal_list = []
+
+	# Diagonals starting from (0,0), for the first row.
+	for i in range(x_max):
+		substring = ""
+		x = i
+		y = 0
+		while x < x_max and y < y_max:
+			#print(x, x_max, y, y_max)
+			substring += list_2d[x][y]
+			x += 1
+			y += 1
+		diagonal_list.append(substring)
+
+	# Reverse
+	diagonal_list = diagonal_list[::-1]
+
+	# Diagonals starting from (0,1), for the first column.
+	for j in range(1, y_max):
+		substring = ""
+		x = 0
+		y = j
+		while x < x_max and y < len(list_2d[x]):
+			substring += list_2d[x][y]
+			x += 1
+			y += 1
+		diagonal_list.append(substring)
+
+	return diagonal_list
+
+def rotate_neg(list_2d):
+	x_max, y_max = len(list_2d), len(list_2d[0])
+	diagonal_list = []
+
+	# Diagonals starting from (0,0), for the first row.
+	for i in range(x_max):
+		substring = ""
+		x = x_max - 1 - i
+		y = 0
+		while x >= 0 and y < y_max:
+			#print(x, x_max, y, y_max)
+			substring += list_2d[x][y]
+			x -= 1
+			y += 1
+		diagonal_list.append(substring)
+
+	# Reverse
+	diagonal_list = diagonal_list[::-1]
+
+	# Diagonals starting from (0,1), for the first column.
+	for j in range(1, y_max):
+		substring = ""
+		x = x_max - 1
+		y = j
+		while x >= 0 and y < len(list_2d[x]):
+			substring += list_2d[x][y]
+			x -= 1
+			y += 1
+		diagonal_list.append(substring)
+
+	return diagonal_list
+
+if __name__ == "__main__":
+	result = 0
+	
+	with open("input", "r") as fp:
+		# Skip last line as it is empty.
+		full_string = fp.read().split("\n")[:-1]
+		for line in full_string:
+			result += scan_line(line)
+			result += scan_line(line[::-1])
+		# Transpose for vertical hits.
+		for line in transpose(full_string):
+			result += scan_line(line)
+			result += scan_line(line[::-1])
+
+		# Rotate 45 degrees to one side for diagonals.
+		diagonal_list = rotate(full_string)
+		for line in diagonal_list:
+			result += scan_line(line)
+			result += scan_line(line[::-1])
+		diagonal_list = rotate_neg(full_string)
+		# Rotate the other way round.
+		for line in diagonal_list:
+			result += scan_line(line)
+			result += scan_line(line[::-1])
+
+	print(f"The sum of all horizontal XMAS's equals {result}.")
+