aoc

commit 912df267a6367396fa0f8ed1fa3700e0948a40cc
parent 5ad6393c60da6a2b2c5c4a796f58a3fc05ed8db9
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date:   Thu, 14 Dec 2023 19:22:23 +0100

Added solution for 14

Diffstat:
A
2023/14/14a.c
 | 
20
++++++++++++++++++++
A
2023/14/14b.c
 | 
105
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 125 insertions(+), 0 deletions(-)
diff --git a/2023/14/14a.c b/2023/14/14a.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+#define N 102
+
+char line[N];
+int i, j, t, s[N], r[N];
+
+int main() {
+	for (i = 0; fgets(line, N, stdin) != NULL; i++) {
+		for (j = 0; line[j] != '\n'; j++) {
+			if (line[j] == '#') s[j] = i+1;
+			if (line[j] == 'O') r[s[j]++]++;
+		}
+	}
+	for (j = 0; j < i; j++)
+		t += r[j] * (i-j);
+
+	printf("%d\n", t);
+	return 0;
+}
diff --git a/2023/14/14b.c b/2023/14/14b.c
@@ -0,0 +1,105 @@
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#define N 102
+#define C 10000
+
+uint64_t h[C];
+char p[C][N][N];
+int e, c, n, t, s[N];
+
+void copy_panel(int c1, int c2) {
+	for (int i = 0; i < n; i++)
+		memcpy(p[c2][i], p[c1][i], n+2);
+}
+
+void tilt_north(void) {
+	for (int i = 0; i < n; i++) s[i] = 0;
+	for (int i = 0; i < n; i++) {
+		for (int j = 0; j < n; j++) {
+			if (p[c][i][j] == '#')
+				s[j] = i+1;
+			if (p[c][i][j] == 'O') {
+				if (s[j] != i) p[c][i][j] = '.';
+				p[c][s[j]++][j] = 'O';
+			}
+		}
+	}
+}
+
+void tilt_west(void) {
+	for (int i = 0; i < n; i++) s[i] = 0;
+	for (int j = 0; j < n; j++) {
+		for (int i = 0; i < n; i++) {
+			if (p[c][i][j] == '#')
+				s[i] = j+1;
+			if (p[c][i][j] == 'O') {
+				if (s[i] != j) p[c][i][j] = '.';
+				p[c][i][s[i]++] = 'O';
+			}
+		}
+	}
+}
+
+void tilt_south(void) {
+	for (int i = 0; i < n; i++) s[i] = n-1;
+	for (int i = n-1; i >= 0; i--) {
+		for (int j = 0; j < n; j++) {
+			if (p[c][i][j] == '#')
+				s[j] = i-1;
+			if (p[c][i][j] == 'O') {
+				if (s[j] != i) p[c][i][j] = '.';
+				p[c][s[j]--][j] = 'O';
+			}
+		}
+	}
+}
+
+void tilt_east(void) {
+	for (int i = 0; i < n; i++) s[i] = n-1;
+	for (int j = n-1; j >= 0; j--) {
+		for (int i = 0; i < n; i++) {
+			if (p[c][i][j] == '#')
+				s[i] = j-1;
+			if (p[c][i][j] == 'O') {
+				if (s[i] != j) p[c][i][j] = '.';
+				p[c][i][s[i]--] = 'O';
+			}
+		}
+	}
+}
+
+bool equal(int c1, int c2) {
+	for (int i = 0; i < n; i++)
+		for (int j = 0; j < n; j++)
+			if (p[c1][i][j] != p[c2][i][j])
+				return false;
+	return true;
+}
+
+int main() {
+	for (n = 0; fgets(p[0][n], N, stdin) != NULL; n++) ;
+
+	for (c = 1; c < C; c++) {
+		copy_panel(c-1, c);
+		tilt_north();
+		tilt_west();
+		tilt_south();
+		tilt_east();
+		for (e = 0; e < c; e++)
+			if (equal(e, c))
+				goto found;
+	}
+
+found:
+	c = (1000000000-e) % (c-e) + e;
+
+	for (int i = 0; i < n; i++)
+		for (int j = 0; j < n; j++)
+			t += (p[c][i][j] == 'O') * (n-i);
+
+	printf("%d\n", t);
+	return 0;
+}