2025(07): solve part 1

2025/07/part1.py

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+import numpy as np
+
+
+debug = False
+
+def load_diagram(filename: str):
+	# Read file as list of strings
+	with open(filename, "r") as fp:
+		data = fp.read().splitlines()
+	
+	data_arr = np.array(data, dtype=str)\
+		.view("U1")\
+		.reshape((len(data), -1))
+
+	return data_arr
+
+def print_diagram(diagram):
+	for line in diagram:
+		for char in line:
+			print(char, end="")
+		print()
+
+def propagate_diagram(in_diagram, inplace=True):
+	diagram = in_diagram.copy() if not inplace else in_diagram
+	ylen = len(diagram)
+
+	# Find start location
+	y0 = 0
+	x0, = np.where(diagram[y0] == "S")[0]
+
+	# Emit starting beam
+	diagram[y0 + 1, x0] = "|"
+	splits_count = 0
+
+	# Propagate the beams, starting with y = 2, as the y = 1 layer has our first beam
+	for y in range(2, ylen):
+		for x in np.where((diagram[y] == "^")&(diagram[y - 1] == "|"))[0]:
+			# NOTE: I do not ever check whether carets are on the boundary.
+			diagram[y, (x - 1, x + 1)] = "|"
+			splits_count += 1
+		for x in np.where((diagram[y] == ".")&(diagram[y - 1] == "|"))[0]:
+			diagram[y, x] = "|"
+		if debug:
+			print_diagram(diagram)
+			print()
+	return splits_count
+
+if __name__ == "__main__":
+	test_diagram = load_diagram("testinput")
+	assert propagate_diagram(test_diagram) == 21
+	
+	diagram = load_diagram("input")
+	print(propagate_diagram(diagram))
+	
+
+def gnonkel(x, a):
+	if x:
+		a += 1
+	
+	# -----
+	if x and y:
+		a+=1
+	elif x:
+		a+=1