110 lines
2.1 KiB
C
110 lines
2.1 KiB
C
#include <stdint.h>
|
|
|
|
#include <stdio.h>
|
|
//#include "printf.h"
|
|
#include "dijkstra.h"
|
|
#include "memory.h"
|
|
|
|
static void parse_sewh(const char * input, int length,
|
|
int * stride,
|
|
int * width, int * height,
|
|
int * start_x, int * start_y,
|
|
int * end_x, int * end_y
|
|
)
|
|
{
|
|
const char * end = input + length;
|
|
|
|
*width = 0;
|
|
*height = 0;
|
|
|
|
while (input < end) {
|
|
char c = *input++;
|
|
|
|
switch (c) {
|
|
case 'S':
|
|
*start_x = *width;
|
|
*start_y = *height;
|
|
break;
|
|
case 'E':
|
|
*end_x = *width;
|
|
*end_y = *height;
|
|
break;
|
|
}
|
|
|
|
*width += 1;
|
|
|
|
if (c == '\n') {
|
|
*stride = *width;
|
|
*width = 0;
|
|
*height += 1;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
*width = *stride - 1;
|
|
}
|
|
|
|
int64_t _2024_day16_part1(const char * input, int length)
|
|
{
|
|
int stride;
|
|
int width;
|
|
int height;
|
|
int start_x;
|
|
int start_y;
|
|
int end_x;
|
|
int end_y;
|
|
|
|
parse_sewh(input, length,
|
|
&stride,
|
|
&width, &height,
|
|
&start_x, &start_y,
|
|
&end_x, &end_y
|
|
);
|
|
|
|
struct dijkstra_xy16 prev[width * height];
|
|
int dist[width * height];
|
|
|
|
dijkstra_cartesian(input,
|
|
stride,
|
|
width, height,
|
|
start_x, start_y,
|
|
end_x, end_y,
|
|
'#',
|
|
prev,
|
|
dist);
|
|
|
|
char map[stride * height + 1];
|
|
memory_copy_char(input, stride * height, map);
|
|
|
|
int x = end_x;
|
|
int y = end_y;
|
|
while (!(x == start_x && y == start_y)) {
|
|
struct dijkstra_xy16 * xy = &prev[y * width + x];
|
|
map[xy->y * stride + xy->x] = 'x';
|
|
x = xy->x;
|
|
y = xy->y;
|
|
}
|
|
map[stride * height] = 0;
|
|
printf("%s", map);
|
|
|
|
return dist[end_y * width + end_x];
|
|
}
|
|
|
|
int64_t _2024_day16_part2(const char * input, int length)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
#include <assert.h>
|
|
|
|
int main()
|
|
{
|
|
FILE * f = fopen("2024/day16/input.txt", "rb");
|
|
const int length = 20022;
|
|
char buf[length];
|
|
size_t len = fread(buf, 1, length, f);
|
|
assert(len == length);
|
|
fclose(f);
|
|
printf("%ld\n", _2024_day16_part1(buf, length));
|
|
}
|