day12

1 files changed, 175 insertions, 0 deletions

diff --git a/2022/day12.c b/2022/day12.c
new file mode 100644
index 0000000..14b92c8
--- /dev/null
+++ b/2022/day12.c
@@ -0,0 +1,175 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "util.h"
+
+s32 reduce(s32 (*f)(s32 x, s32 y), s32 arr[], s32 len)
+{
+	s32 ret = arr[0];
+
+	for (s32 i = 1; i < len; ++i) {
+		ret = f(ret, arr[i]);
+	}
+
+	return ret;
+}
+
+s32 mul(s32 x, s32 y)
+{
+	return x * y;
+}
+
+s32 max(s32 x, s32 y)
+{
+	return x > y ? x : y;
+}
+
+s32 count_char_in_string(char c, char *s)
+{
+	s32 count = 0;
+	do
+		if (c == *s)
+			count++;
+	while (*s++);
+	return count;
+}
+
+char *goto_char_in_string(char c, char *s)
+{
+	do
+		if (c == *s)
+			return s;
+	while (*s++);
+	return NULL;
+}
+
+#define PP(arr, y,x) (*(*(arr+y)+x))
+
+char filename[] = "in/day12.ref";
+// char filename[] = "in/day12.pzl";
+
+#define BUF_LEN 10000
+char file_buf[BUF_LEN];
+
+s32 **grid;
+s32 **visited;
+s32 y_len;
+s32 x_len;
+s32 start_y;
+s32 start_x;
+s32 end_y;
+s32 end_x;
+
+s32 traverse(s32 steps,s32 y, s32 x)
+{
+	if (PP(visited,y,x) < steps) {
+		return 42000;
+	}
+	PP(visited,y,x) = steps;
+	// if (PP(visited,y,x) == 1) {
+	// 	return 12345;
+	// }
+	// PP(visited,y,x) = 1;
+
+	if ((x==end_x) && (y==end_y)) {
+		return steps;
+	}
+
+	s32 min = 123456;
+
+	if ( (x+1 < x_len) && (PP(grid,y,x+1) <= (PP(grid,y,x)+1)) ) {
+		s32 a = traverse(steps+1, y, x+1);
+		if (a < min) {
+			min = a;
+		}
+	}
+	if ( (x > 0) && (PP(grid,y,x-1) <= (PP(grid,y,x)+1)) ) {
+		s32 a = traverse(steps+1, y, x-1);
+		if (a < min) {
+			min = a;
+		}
+	}
+	if ( (y+1 < y_len) && (PP(grid,y+1,x) <= (PP(grid,y,x)+1)) ) {
+		s32 a = traverse(steps+1, y+1, x);
+		if (a < min) {
+			min = a;
+		}
+	}
+	if ( (y > 0) && (PP(grid,y-1,x) <= (PP(grid,y,x)+1)) ) {
+		s32 a = traverse(steps+1, y-1, x);
+		if (a < min) {
+			min = a;
+		}
+	}
+
+	return min;
+}
+
+
+int main()
+{
+	int fd = open(filename, O_RDONLY);
+	s32 data_len = read(fd, file_buf, LEN(file_buf));
+
+	if (data_len == -1) {
+		printf("error opening file\n");
+		exit(1);
+	} else if (data_len == LEN(file_buf)) {
+		printf("buffer probably not big enough\n");
+		exit(1);
+	}
+	file_buf[data_len] = '\0';
+
+	y_len = count_char_in_string('\n', file_buf);
+
+
+	grid = malloc(y_len * sizeof(s32*));
+	visited = malloc(y_len * sizeof(s32*));
+	char *start  = file_buf;
+
+	for (s32 y = 0; y < y_len; ++y) {
+		char *end = goto_char_in_string('\n', start);
+		x_len = end - start;
+
+		*(grid+y) = malloc(x_len * sizeof(s32*));
+		*(visited+y) = malloc(x_len * sizeof(s32*));
+
+		for (s32 x = 0; x < x_len; ++x) {
+			char c = *(start + x);
+			if (c == 'S') {
+				start_y = y;
+				start_x = x;
+				c = 'a';
+			} else if (c == 'E') {
+				end_y = y;
+				end_x = x;
+				c = 'z';
+			}
+			*(*(grid+y) + x) = c - 'a';
+			*(*(visited+y) + x) = 123456;
+			// *(*(visited+y) + x) = 0;
+		}
+		start = end+1;
+	}
+	printf("y_len: %d\n", y_len);
+	printf("x_len: %d\n", x_len);
+
+	printf("start y: %d\n", start_y);
+	printf("start x: %d\n", start_x);
+	printf("end y: %d\n", end_y);
+	printf("end x: %d\n", end_x);
+
+
+
+	s32 res1 = 0;
+	s32 res2 = 0;
+
+	res1 = traverse(0, start_y, start_x);
+
+
+	printf("res1: %d\n", res1);
+	printf("res2: %d\n", res2);
+	// asm("int3");
+}
+