My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Update 2018/11 solution
Hooray for partial sums.
+24
-31
+24
-31
2018/day11.py
+24
-31
2018/day11.py
···
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import fileinput
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SIZE = 300
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def power_level(x, y, serial):
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x += 1
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y += 1
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rack_id = x + 10
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return (((rack_id * y + serial) * rack_id // 100) % 10) - 5
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SERIAL = int(fileinput.input()[0])
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SIZE = 300
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GRID = [[power_level(x, y, SERIAL) for x in range(SIZE)] for y in range(SIZE)]
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def power_search(partials, conv_size):
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best_power = 0
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best_x = 0
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best_y = 0
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overall_sum = 0
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overall_x = 0
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overall_y = 0
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overall_size = 0
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for y in range(1, SIZE - conv_size + 1):
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for x in range(1, SIZE - conv_size + 1):
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xx = x + conv_size
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yy = y + conv_size
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power = PARTIALS[yy][xx] + PARTIALS[y][x] - PARTIALS[y][xx] - PARTIALS[yy][x]
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for size in range(3, 16): # window size of 16 is good enough...right?
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best_sum = 0
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best_x = 0
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best_y = 0
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if power > best_power:
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best_power = power
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best_x = x + 1
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best_y = y + 1
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for y in range(SIZE - size):
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for x in range(SIZE - size):
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total = 0
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for j in range(size):
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for i in range(size):
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total += GRID[y + j][x + i]
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return best_power, best_x, best_y, conv_size,
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if total > best_sum:
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best_sum = total
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best_x = x
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best_y = y
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if size == 3:
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print "Coordinate of most powerful 3x3 grid: {},{}".format(best_x + 1, best_y + 1)
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SERIAL = int(fileinput.input()[0])
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PARTIALS = [[0 for _ in range(SIZE + 1)] for _ in range(SIZE + 1)]
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if best_sum > overall_sum:
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overall_sum = best_sum
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overall_x = best_x
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overall_y = best_y
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overall_size = size
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for y in range(1, SIZE + 1):
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for x in range(1, SIZE + 1):
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PARTIALS[y][x] = power_level(x, y, SERIAL) + PARTIALS[y][x-1] + PARTIALS[y-1][x] - PARTIALS[y-1][x-1]
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print "Identifier of the largest total power: {},{},{}".format(overall_x + 1, overall_y + 1, overall_size)
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print "Coordinate of most powerful 3x3 grid: {1},{2}".format(*power_search(PARTIALS, 3))
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print "Identifier of the largest total power: {1},{2},{3}".format(*max(power_search(PARTIALS, n) for n in range(1, SIZE)))