1 files changed, 144 insertions, 0 deletions
diff --git a/2020/17/solve.c b/2020/17/solve.c
new file mode 100644
index 0000000..5053d97
--- /dev/null
+++ b/2020/17/solve.c
@@ -0,0 +1,144 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#define SIZE 30
+#define X_SIZE SIZE
+#define Y_SIZE SIZE
+#define Z_SIZE SIZE
+#define W_SIZE SIZE
+#define X_START (X_SIZE / 2)
+#define Y_START (Y_SIZE / 2)
+#define Z_START (Z_SIZE / 2)
+#define W_START (W_SIZE / 2)
+
+int part_one(FILE *fp)
+{
+	int res = 0;
+
+	static char dat[X_SIZE][Y_SIZE][Z_SIZE] = { 0 };
+	static char new[X_SIZE][Y_SIZE][Z_SIZE] = { 0 };
+
+	char c;
+	int x = X_START, y = Y_START, z = Z_START;
+	for (; (c = fgetc(fp)) != EOF; x++) {
+		if (c == '#') {
+			dat[z][y][x] = 1;
+			res++;
+		} else if (c == '\n') {
+			x = X_START - 1;
+			y++;
+		}
+	}
+
+	for (int i = 0; i < 6; i++) {
+		memset(new, 0, X_SIZE * Y_SIZE * Z_SIZE);
+		// LOL
+		for (int z = 1; z < Z_SIZE - 1; z++)
+			for (int y = 1; y < Y_SIZE - 1; y++)
+				for (int x = 1; x < X_SIZE - 1; x++)
+					for (int z2 = z - 1; z2 < z + 2; z2++)
+						for (int y2 = y - 1; y2 < y + 2; y2++)
+							for (int x2 = x - 1; x2 < x + 2; x2++)
+								if ((z != z2 || y != y2 ||
+								     x != x2) &&
+								    dat[z2][y2][x2])
+									new[z][y][x]++;
+		for (int z = 1; z < Z_SIZE - 1; z++)
+			for (int y = 1; y < Y_SIZE - 1; y++)
+				for (int x = 1; x < X_SIZE - 1; x++)
+					if ((new[z][y][x] == 2 && dat[z][y][x]) ||
+					    new[z][y][x] == 3) {
+						if (dat[z][y][x])
+							continue;
+						dat[z][y][x] = 1;
+						res++;
+					} else {
+						if (!dat[z][y][x])
+							continue;
+						dat[z][y][x] = 0;
+						res--;
+					}
+	}
+
+	return res;
+}
+
+int part_two(FILE *fp)
+{
+	int res = 0;
+
+	static char dat[W_SIZE][X_SIZE][Y_SIZE][Z_SIZE] = { 0 };
+	static char new[W_SIZE][X_SIZE][Y_SIZE][Z_SIZE] = { 0 };
+
+	char c;
+	int x = X_START, y = Y_START, z = Z_START, w = W_START;
+	for (; (c = fgetc(fp)) != EOF; x++) {
+		if (c == '#') {
+			dat[w][z][y][x] = 1;
+			res++;
+		} else if (c == '\n') {
+			x = X_START - 1;
+			y++;
+		}
+	}
+
+	for (int i = 0; i < 6; i++) {
+		memset(new, 0, X_SIZE * Y_SIZE * Z_SIZE);
+		// LOL LOL
+		for (int w = 1; w < W_SIZE - 1; w++)
+			for (int z = 1; z < Z_SIZE - 1; z++)
+				for (int y = 1; y < Y_SIZE - 1; y++)
+					for (int x = 1; x < X_SIZE - 1; x++)
+						for (int w2 = w - 1; w2 < w + 2; w2++)
+							for (int z2 = z - 1; z2 < z + 2; z2++)
+								for (int y2 = y - 1; y2 < y + 2;
+								     y2++)
+									for (int x2 = x - 1;
+									     x2 < x + 2; x2++)
+										if ((w != w2 ||
+										     z != z2 ||
+										     y != y2 ||
+										     x != x2) &&
+										    dat[w2][z2][y2]
+										       [x2])
+											new[w][z][y]
+											   [x]++;
+		for (int w = 1; w < W_SIZE - 1; w++)
+			for (int z = 1; z < Z_SIZE - 1; z++)
+				for (int y = 1; y < Y_SIZE - 1; y++)
+					for (int x = 1; x < X_SIZE - 1; x++)
+						if ((new[w][z][y][x] == 2 && dat[w][z][y][x]) ||
+						    new[w][z][y][x] == 3) {
+							if (dat[w][z][y][x])
+								continue;
+							dat[w][z][y][x] = 1;
+							res++;
+						} else {
+							if (!dat[w][z][y][x])
+								continue;
+							dat[w][z][y][x] = 0;
+							res--;
+						}
+	}
+
+	return res;
+}
+
+int main(int argc, char *argv[])
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	clock_t tic = clock();
+	printf("%d\n", part_one(fp));
+	rewind(fp);
+	printf("%d\n", part_two(fp));
+	clock_t toc = clock();
+	printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);
+
+	fclose(fp);
+	return 0;
+}