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#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");
}
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