12 files changed, 188 insertions, 0 deletions
diff --git a/aoc/2022/10/part-one.awk b/aoc/2022/10/part-one.awk
new file mode 100755
index 0000000..756464e
--- /dev/null
+++ b/aoc/2022/10/part-one.awk
@@ -0,0 +1,8 @@
+#!/usr/bin/env -S awk -f
+BEGIN { cycle = x = 1 }
+{ cycle++ }
+cycle % 40 == 20 { strength += cycle * x }
+{ x += $2 }
+/^addx/ { cycle++ }
+/^addx/ && cycle % 40 == 20 { strength += cycle * x }
+END { print strength }
diff --git a/aoc/2022/10/part-two.awk b/aoc/2022/10/part-two.awk
new file mode 100755
index 0000000..9126306
--- /dev/null
+++ b/aoc/2022/10/part-two.awk
@@ -0,0 +1,10 @@
+#!/usr/bin/env -S awk -f
+function cycle (c, x) {
+  printf x - 2 < c && c < x + 2 ? "#" : "."
+  printf c == 39 ? "\n" : ""
+  return (c + 1) % 40
+}
+BEGIN { x = 1 }
+{ c = cycle(c, x) }
+/^addx/ { c = cycle(c, x) }
+{ x += $2 }
diff --git a/aoc/2024/01/part-one.py b/aoc/2024/01/part-one.py
new file mode 100644
index 0000000..2a2421e
--- /dev/null
+++ b/aoc/2024/01/part-one.py
@@ -0,0 +1,4 @@
+from sys import stdin
+
+left, right = zip(*((int(a), int(b)) for a, b in map(str.split, stdin)))
+print(sum(map(abs, map(int.__sub__, sorted(left), sorted(right)))))
diff --git a/aoc/2024/01/part-two.py b/aoc/2024/01/part-two.py
new file mode 100644
index 0000000..5000c9c
--- /dev/null
+++ b/aoc/2024/01/part-two.py
@@ -0,0 +1,6 @@
+from sys import stdin
+from collections import Counter
+
+left, right = zip(*((int(a), int(b)) for a, b in map(str.split, stdin)))
+counter = Counter(right)
+print(sum(counter[n]*n for n in left))
diff --git a/aoc/2024/02/part-one.py b/aoc/2024/02/part-one.py
new file mode 100644
index 0000000..e0d74db
--- /dev/null
+++ b/aoc/2024/02/part-one.py
@@ -0,0 +1,6 @@
+from sys import stdin
+
+print(sum(all(0 < d < 4 for d in diffs) or all(-4 < d < 0 for d in diffs)
+          for diffs in (tuple(map(int.__sub__, levels, levels[1:]))
+                        for levels in (tuple(map(int, line))
+                                       for line in map(str.split, stdin)))))
diff --git a/aoc/2024/02/part-two.py b/aoc/2024/02/part-two.py
new file mode 100644
index 0000000..ad5f5a6
--- /dev/null
+++ b/aoc/2024/02/part-two.py
@@ -0,0 +1,21 @@
+from collections import Counter
+from itertools import chain, count
+from sys import stdin
+
+
+def safe(levels, dampened=False):
+    head = levels[0 if 0 < levels[1] - levels[0] < 4 else 1] - 1,
+    tail = levels[-1 if 0 < levels[-1] - levels[-2] < 4 else -2] + 1,
+    dampenable = tuple((not dampened and 0 < a - c < 4
+                        and safe(levels[:i]+levels[i+1:], True))
+                       for i, a, b, c in zip(count(),
+                                             chain(levels[1:], tail),
+                                             levels,
+                                             chain(head, levels))
+                       if not (0 < a - b < 4 and 0 < b - c < 4))
+    return not dampenable or any(dampenable)
+
+
+print(sum(safe(levels) or safe(tuple(map(int.__neg__, levels)))
+          for levels in (tuple(map(int, line))
+                         for line in map(str.split, stdin))))
diff --git a/aoc/2024/03/part-one.c b/aoc/2024/03/part-one.c
new file mode 100644
index 0000000..0438304
--- /dev/null
+++ b/aoc/2024/03/part-one.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int main()
+{
+	size_t x, y, s = 0;
+	while (scanf("%*[^m]") != EOF)
+		if (scanf("mul(%3zu,%3zu", &x, &y) == 2 && getchar() == ')')
+			s += x * y;
+	printf("%zu\n", s);
+	return 0;
+}
diff --git a/aoc/2024/03/part-two.c b/aoc/2024/03/part-two.c
new file mode 100644
index 0000000..4ae337f
--- /dev/null
+++ b/aoc/2024/03/part-two.c
@@ -0,0 +1,27 @@
+#include <stdbool.h>
+#include <stdio.h>
+
+int main()
+{
+	bool d = true;
+	size_t x, y, s = 0;
+	while (scanf("%*[^dm]") != EOF) {
+		if (getchar() == 'd') {
+			int c;
+#define unless(i) if ((c = getchar()) != i && ungetc(c, stdin) == c)
+			unless ('o') continue;
+			unless ('(') {
+				if (scanf("n't()") != EOF)
+					d = false;
+				continue;
+			}
+			unless (')') continue;
+#undef unless
+			d = true;
+		}
+		if (scanf("ul(%3zu,%3zu", &x, &y) == 2 && getchar() == ')' && d)
+			s += x * y;
+	}
+	printf("%zu\n", s);
+	return 0;
+}
diff --git a/aoc/2024/04/part-one.py b/aoc/2024/04/part-one.py
new file mode 100644
index 0000000..ba25336
--- /dev/null
+++ b/aoc/2024/04/part-one.py
@@ -0,0 +1,23 @@
+from sys import stdin
+
+
+def index(m, n, i, j, c):
+    return (m[i][j], m[n-j-1][i], m[n-i-1][n-j-1], m[j][n-i-1])[c]
+
+
+def rot(m, c):
+    n = len(m)
+    if n != len(m[0]): raise ValueError
+    for i in range(n):
+        yield ''.join(index(m, n, i-j, j, c) for j in range(i+1))
+    for i in range(1, n):
+        yield ''.join(index(m, n, n-j-1, i+j, c) for j in range(n-i))
+
+
+reverse_all = lambda strings: (s[::-1] for s in strings)
+count = lambda strings: sum(s.count('XMAS') for s in strings)
+lines = tuple(map(str.strip, stdin.readlines()))
+columns = tuple(''.join(column) for column in zip(*lines))
+print((count(lines) + count(reverse_all(lines))
+       + count(columns) + count(reverse_all(columns))
+       + sum(count(rot(lines, c)) for c in range(4))))
diff --git a/aoc/2024/04/part-two.py b/aoc/2024/04/part-two.py
new file mode 100644
index 0000000..a3e7c4a
--- /dev/null
+++ b/aoc/2024/04/part-two.py
@@ -0,0 +1,10 @@
+from itertools import islice
+from sys import stdin
+
+mat = tuple(map(str.strip, stdin.readlines()))
+m = len(mat)
+n = len(mat[0])
+print(sum(c == 'A' and ({mat[i-1][j-1], mat[i+1][j+1]}
+                        == {mat[i-1][j+1], mat[i+1][j-1]} == {'M', 'S'})
+          for i, line in islice(enumerate(mat), 1, m-1)
+          for j, c in islice(enumerate(line), 1, n-1)))
diff --git a/aoc/2024/05/part-one.c b/aoc/2024/05/part-one.c
new file mode 100644
index 0000000..4d2b560
--- /dev/null
+++ b/aoc/2024/05/part-one.c
@@ -0,0 +1,27 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main()
+{
+	bool after[100][100] = {false};
+	unsigned char x, y;
+	while (scanf("%hhu|%hhu\n", &x, &y) == 2)
+		after[y][x] = true;
+
+	unsigned char line[90];
+	unsigned sum = y = 0;
+	do {
+		bool right = true;
+		do {
+			line[y] = x;
+			for (unsigned char i = 0; right && i < y; ++i)
+				if (after[line[i]][line[y]])
+					right = false;
+		} while (scanf(",%hhu", &x) == 1 && ++y);
+		if (right)
+			sum += line[y + 1 >> 1];
+	} while (y = 0, scanf("%hhu", &x) == 1);
+	printf("%u\n", sum);
+	return 0;
+}
diff --git a/aoc/2024/05/part-two.c b/aoc/2024/05/part-two.c
new file mode 100644
index 0000000..443e8b0
--- /dev/null
+++ b/aoc/2024/05/part-two.c
@@ -0,0 +1,35 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static bool after[100][100];
+
+int compare(const void *x, const void *y)
+{
+	return after[*(const unsigned char *) x][*(const unsigned char *) y];
+}
+
+int main()
+{
+	unsigned char x, y;
+	while (scanf("%hhu|%hhu\n", &x, &y) == 2)
+		after[y][x] = true;
+
+	unsigned char line[90];
+	unsigned sum = y = 0;
+	do {
+		bool right = true;
+		do {
+			line[y] = x;
+			for (unsigned char i = 0; right && i < y; ++i)
+				if (after[line[i]][line[y]])
+					right = false;
+		} while (scanf(",%hhu", &x) == 1 && ++y);
+		if (right)
+			continue;
+		qsort(line, ++y, 1, compare);
+		sum += line[y >> 1];
+	} while (y = 0, scanf("%hhu", &x) == 1);
+	printf("%u\n", sum);
+	return 0;
+}