Begin work on 2018-11

2018/11/solve.py

@@ -0,0 +1,79 @@
+import sys
+
+# PART 1
+
+def nth_digit(num, pos):
+	# nth_digit(1234, 0) = 123[4] = 4
+	# nth_digit(1234, 2) = 1[2]34 = 2
+	# nth_digit(1234, 4) = [0]1234 = 0
+
+	pos += 1
+	s = ("{:0" + str(pos) + "}").format(num) # UGLY!
+	n = s[-pos]
+	return int(n)
+
+def power_level(number, x, y):
+	rack_id = x + 10
+	level = rack_id * y
+	level += number
+	level *= rack_id
+	level = nth_digit(level, 2) # 100-er digit
+	level -= 5
+	return level
+
+def init_grid(number):
+	grid = {}
+	for x in range(1, 300 + 1):
+		for y in range(1, 300 + 1):
+			grid[(x, y)] = power_level(number, x, y)
+	return grid
+
+def power_of_square(grid, x, y):
+	power = 0
+	for dx in range(3):
+		for dy in range(3):
+				power += grid[(x+dx, y+dy)]
+	return power
+
+def find_max_power(grid):
+	max_power = 0
+	max_coords = None
+
+	for x in range(1, 300 - 2 + 1):
+		for y in range(1, 300 - 2 + 1):
+			power = power_of_square(grid, x, y)
+			if power > max_power:
+				max_power = power
+				max_coords = (x, y)
+	
+	return max_coords
+
+# PART 2
+
+def square_power(grid, x, y, size):
+	pass
+
+def max_square(grid):
+	max_power = 0
+	max_coords = None
+	max_size = None
+
+	for size in range(1, 300 + 1):
+		for x in range(1, 300 + 1 - (size - 1)):
+			for y in range(1, 300 + 1 - (size - 1)):
+				pass
+
+def main(number):
+	print(f"Solutions for {number}")
+	grid = init_grid(number)
+	x, y = find_max_power(grid)
+	print(f"Part 1: {x},{y}")
+	print(f"Part 2: NYI")
+
+if __name__ == "__main__":
+	print(power_level( 8,   3,   5))
+	print(power_level(57, 122,  79))
+	print(power_level(39, 217, 196))
+	print(power_level(71, 101, 153))
+
+	main(5153)