yay

1 files changed, 77 insertions, 33 deletions

diff --git a/2021/24/solve.c b/2021/24/solve.c
index 72bf9de..8eff5f3 100644
--- a/2021/24/solve.c
+++ b/2021/24/solve.c
@@ -1,45 +1,89 @@
-#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <time.h>
 
-// Non-trial-and-error solution in solve.js
+#define COUNT(a) ((int)(sizeof(a) / sizeof 0 [a]))
 
-static const int xs[] = { 14, 14, 14, 12, 15, -12, -12, 12, -7, 13, -8, -5, -10, -7 };
-static const int ys[] = { 14, 2, 1, 13, 5, 5, 5, 9, 3, 13, 2, 1, 11, 8 };
-static const int zs[] = { 1, 1, 1, 1, 1, 26, 26, 1, 26, 1, 26, 26, 26, 26 };
+#define FORLINE                                                                                    \
+	char *line = NULL;                                                                         \
+	size_t len = 0;                                                                            \
+	while (getline(&line, &len, fp) != EOF)
+#define FREELINE                                                                                   \
+	if (line)                                                                                  \
+	free(line)
 
-int main(int argc, char *argv[])
+typedef char block[17][16];
+
+struct data {
+	int idx;
+	int value;
+};
+
+typedef char out[15];
+
+static void solve(FILE *fp)
 {
-	srand(time(0));
-	long w = 19599999999999;
-
-	char ws[15];
-	while (1) {
-		sprintf(ws, "%lu", w);
-
-		long x = 0, y = 0, z = 0;
-		for (int i = 0; i < 14; i++) {
-			x = z;
-			x %= 26;
-			z /= zs[i];
-			x += xs[i];
-			x = (x == (ws[i] - '0')) ? 0 : 1;
-			y = 25;
-			y *= x;
-			y += 1;
-			z *= y;
-			y = (ws[i] - '0') + ys[i];
-			y *= x;
-			z += y;
+	block blocks[14] = { 0 };
+	int block_idx = -1;
+	int line_idx = 0;
+	FORLINE
+	{
+		if (line[0] == 'i') {
+			block_idx++;
+			line_idx = 0;
+			continue;
+		}
+
+		strcpy(blocks[block_idx][line_idx++], line);
+	};
+	FREELINE;
+
+	out min = { 0 }, max = { 0 };
+
+	struct data arr[100] = { 0 };
+	int idx = 0;
+
+	for (int i = 0; i < COUNT(blocks); i++) {
+		if (blocks[i][3][6] == '1') {
+			int num;
+			sscanf(blocks[i][14], "add y %d", &num);
+			arr[idx++] = (struct data){ i, num };
+			continue;
 		}
-		if (z == 0) {
-			printf("Found %ld %ld %ld -> %ld\n", w, x, y, z);
-			break;
+
+		int num;
+		sscanf(blocks[i][4], "add x %d", &num);
+		struct data data = arr[--idx];
+		int d = data.value + num, j = i;
+		if (d < 0) {
+			j = data.idx;
+			data.idx = i;
+			d *= -1;
 		}
-		if (w % 100000 == 0)
-			printf("%ld %ld\n", w, z);
-		w--;
+		max[j] = '9';
+		max[data.idx] = 9 - d + '0';
+		min[j] = 1 + d + '0';
+		min[data.idx] = '1';
 	}
+
+	printf("%s\n%s\n", max, min);
+}
+
+int main(int argc, char *argv[])
+{
+	(void)argc;
+	(void)argv;
+
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	clock_t tic = clock();
+	solve(fp);
+	clock_t toc = clock();
+	printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);
+
+	fclose(fp);
 	return 0;
 }