💣

.gitignore

+*.dat
+__pycache__/
+.DS_Store
+venv/

makefile

+FILE = $(shell find . -name p??.py -type f | xargs ls -rt | tail -n 1)
+DATA = $(shell echo $(FILE) | sed -e s/\.py/\.dat/)
+PYTHONPATH=.
+
+main: venv/
+	@touch $(DATA)
+	@cat $(DATA) | venv/bin/python -u $(FILE)
+
+venv/: requirements.txt
+	rm -rf venv/
+	python3 -m venv venv
+	venv/bin/pip install -r requirements.txt
+	touch requirements.txt venv/

requirements.txt

+pypng
+numpy
+scipy
+scikit-image

y2018/p17.py

+import collections
+import re
+from pathlib import Path
+
+
+def read_in():
+    grid = collections.defaultdict(lambda: ' ')
+    for _ in Path('y2018/p17.dat').read_text().splitlines():
+        _ = _.replace(',', ';')
+        _ = re.sub(r'(\d+)\.\.(\d+)', r'range(\1, \2 + 1)', _)
+        _ = re.sub(r'=(\d+)', r'=[\1]', _)
+        exec(_, globals())
+        grid.update({(X, Y): '#' for X in x for Y in y})
+    return grid
+
+
+def write_out(grid, path):
+    text = '\n'.join(
+        ''.join(grid[x, y] for x in range(xmin - 5, xmax + 5))
+        for y in range(ymin, ymax + 1)
+    )
+    Path(path).write_text(text)
+
+
+def flow(start):
+    stack = [start]
+    while stack:
+        x, y = stack.pop()
+        grid[x, y] = '~'
+
+        if y > ymax:
+            break
+
+        for dx, dy in [(1, 0), (-1, 0), (0, 1)]:
+            new = x + dx, y + dy
+            if dy == 1 and grid[new] == '|':
+                stack.clear()
+                break
+
+            if grid[new] == ' ':
+                stack.append(new)
+
+    drain((x, y))
+
+
+def drain(end):
+    stack = [end]
+    while stack:
+        x, y = stack.pop()
+        grid[x, y] = '|'
+
+        if grid[x - 1, y] == '|' and grid[x + 1, y] == ' ' and grid[x, y + 1] != '|':
+            flow((x + 1, y))
+
+        for dx, dy in [(-1, 0), (1, 0), (0, -1)]:
+            new = x + dx, y + dy
+            if grid[new] == '~':
+                stack.append(new)
+
+
+grid = read_in()
+xmin, *_, xmax = sorted(x for x, y in grid)
+ymin, *_, ymax = sorted(y for x, y in grid)
+flow((500, 0))
+counter = collections.Counter(grid.values())
+print(counter['~'] + counter['|'])
+print(counter['~'])
+write_out(grid, 'y2018/p17out.dat')

y2019/intcode.py

+import re
+
+
+def parse(string):
+    return [int(n) for n in re.findall(r'-?\d+', string)]
+
+
+def get_parameters(ns, pos, modes, N, writes):
+    for c in writes:
+        # paradox: return immediate mode to use positionally outside
+        modes[ord(c) - ord('a')] = '1'
+
+    for mode, x in zip(modes, ns[pos:][:N]):
+        yield {
+            '0': lambda: ns[x],
+            '1': lambda: x,
+        }[mode]()
+
+    yield pos + N
+
+
+def compute(ns, inp):
+    if isinstance(ns, str):
+        ns = parse(ns)
+
+    pos = 0
+    consume = lambda n, writes='': get_parameters(ns, pos, modes, n, writes)
+
+    while True:
+        op = ns[pos] % 100
+        # instructions stupidly say ABC referring to parameters 3, 2, 1
+        # we do a, b, c
+        modes = list(str(ns[pos] // 100).zfill(3)[::-1])
+        pos += 1
+
+        if op == 1:
+            a, b, c, pos = consume(3, 'c')
+            ns[c] = a + b
+
+        elif op == 2:
+            a, b, c, pos = consume(3, 'c')
+            ns[c] = a * b
+
+        elif op == 3:
+            a, pos = consume(1, 'a')
+            ns[a] = inp
+
+        elif op == 4:
+            a, pos = consume(1)
+            yield a
+
+        elif op == 5:
+            a, b, pos = consume(2)
+            if a != 0:
+                pos = b
+
+        elif op == 6:
+            a, b, pos = consume(2)
+            if a == 0:
+                pos = b
+
+        elif op == 7:
+            a, b, c, pos = consume(3, 'c')
+            ns[c] = int(a < b)
+
+        elif op == 8:
+            a, b, c, pos = consume(3, 'c')
+            ns[c] = int(a == b)
+
+        elif op == 99:
+            return
+
+        else:
+            raise RuntimeError(op)

y2019/p01.py

+import sys
+
+
+text = sys.stdin.read()
+ns = [int(s) for s in text.splitlines()]
+
+
+def handle(n):
+    m = n // 3 - 2
+    return [m] + handle(m) if m > 0 else []
+
+
+if __name__ == '__main__':
+    print(sum(handle(n)[0] for n in ns))
+    print(sum(sum(handle(n)) for n in ns))

y2019/p02.py

+import itertools
+import re
+import sys
+from intcode import compute, parse
+
+
+def check(noun, verb):
+    ns = parse(text)
+    ns[1:3] = [noun, verb]
+    list(compute(ns, 2))
+    return ns[0]
+
+
+text = sys.stdin.read()
+print(check(12, 2))
+for noun, verb in itertools.product(range(100), repeat=2):
+    if check(noun, verb) == 19690720:
+        print(100 * noun +  verb)

y2019/p03.py

+import sys
+
+
+text = sys.stdin.read()
+maps = {'R': -1, 'D': -1j, 'L': 1, 'U': 1j}
+
+
+info = []
+for path in text.splitlines():
+    i, p = 0, 0
+    best = {}
+    for a, *n in path.split(','):
+        d = maps[a]
+        for _ in range(int(''.join(n))):
+            i += 1
+            p += d
+            if p not in best:
+                best[p] = i
+    info.append(best)
+
+
+isect = set(info[0]) & set(info[1])
+print(int(min((abs(p.real) + abs(p.imag), p) for p in isect)[0]))
+print(min(info[0][p] + info[1][p] for p in isect))

y2019/p04.py

+import sys
+import itertools
+
+strings = [str(n) for n in range(347312, 805915 + 1)]
+print(sum(list(s) == sorted(s) and any(len(list(vs)) >= 2 for k, vs in itertools.groupby(s)) for s in strings))
+print(sum(list(s) == sorted(s) and any(len(list(vs)) == 2 for k, vs in itertools.groupby(s)) for s in strings))

y2019/p05.py

+import sys
+from intcode import compute, parse
+
+
+tests = [
+    ('3,0,4,0,99', [(12421, 12421)]),
+    ('3,9,8,9,10,9,4,9,99,-1,8', [(8, 1), (7, 0)]),
+    ('3,9,7,9,10,9,4,9,99,-1,8', [(7, 1), (8, 0), (9, 0)]),
+    ('3,12,6,12,15,1,13,14,13,4,13,99,-1,0,1,9', [(0, 0), (213, 1)]),
+    ('3,3,1105,-1,9,1101,0,0,12,4,12,99,1', [(0, 0), (213, 1)]),
+    ('''
+        3,21,1008,21,8,20,1005,20,22,107,8,21,20,1006,20,31,
+        1106,0,36,98,0,0,1002,21,125,20,4,20,1105,1,46,104,
+        999,1105,1,46,1101,1000,1,20,4,20,1105,1,46,98,99
+    ''', [(7, 999), (8, 1000), (9, 1001)]),
+]
+
+
+for program, pairs in tests:
+    for inp, expect in pairs:
+        out = list(compute(program, inp))[-1]
+        assert out == expect, (out, expect)
+
+
+text = sys.stdin.read()
+print(list(compute(text, 1))[-1])
+print(list(compute(text, 5))[-1])