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#include "allocator.h"
#include "hmap.h"
#include "hmap_s.h"
#include "aoc.h"
#include "vec_s.h"
#include "dvec_s.h"
#include "util.h"
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
struct layer {
char cells[5][5];
uint8_t adj[5][5];
};
struct cell {
size_t adj;
char c;
};
static void
load_map(struct hmap *map)
{
const char *lpos, *lend;
struct layer *layer;
size_t x, y, len;
char line[256];
y = 0;
layer = malloc(sizeof(struct layer));
lpos = aoc.input;
lend = lpos + aoc.input_size;
while (readtok(line, sizeof(line), '\n', &lpos, lend)) {
len = strlen(line);
for (x = 0; x < len; x++)
layer->cells[y][x] = line[x];
y += 1;
}
hmap_add(map, (struct hmap_key) {.ss = 0},
(struct hmap_val) {.p = layer});
}
static void
print_layer(struct hmap *map, ssize_t z)
{
struct hmap_link *link;
const struct layer *layer;
size_t x, y;
link = hmap_get(map, (struct hmap_key) {.ss = z});
if (link) layer = link->value.p;
for (y = 0; y < 5; y++) {
for (x = 0; x < 5; x++) {
if (x == 2 && y == 2) {
aoc_debug("?");
} else if (link) {
aoc_debug("%c", layer->cells[y][x]);
} else {
aoc_debug(".");
}
}
aoc_debug("\n");
}
}
static void
print_layers(struct hmap *map, ssize_t minz, ssize_t maxz)
{
ssize_t z;
for (z = minz; z <= maxz; z++) {
aoc_debug("Z %li\n", z);
print_layer(map, z);
aoc_debug("\n");
}
}
static size_t
map_count(struct hmap *map)
{
const struct layer *layer;
struct hmap_iter iter;
size_t x, y, count;
count = 0;
for (HMAP_ITER(map, iter)) {
layer = iter.link->value.p;
for (y = 0; y < 5; y++) {
for (x = 0; x < 5; x++) {
if (x == 2 && y == 2)
continue;
if (layer->cells[y][x] == '#')
count += 1;
}
}
}
return count;
}
static size_t
top_cells(const struct layer *layer)
{
size_t i, count;
count = 0;
for (i = 0; i < 5; i++)
count += layer->cells[0][i] == '#';
return count;
}
static size_t
right_cells(const struct layer *layer)
{
size_t i, count;
count = 0;
for (i = 0; i < 5; i++)
count += layer->cells[i][4] == '#';
return count;
}
static size_t
bottom_cells(const struct layer *layer)
{
size_t i, count;
count = 0;
for (i = 0; i < 5; i++)
count += layer->cells[4][i] == '#';
return count;
}
static size_t
left_cells(const struct layer *layer)
{
size_t i, count;
count = 0;
for (i = 0; i < 5; i++)
count += layer->cells[i][0] == '#';
return count;
}
static size_t
cell_count(struct hmap *map, struct layer *layer,
struct vec2i *pos, size_t dir, ssize_t z)
{
struct hmap_link *link;
const struct layer *nlayer;
size_t count;
count = 0;
if (pos->x == 2 && pos->y == 2) {
link = hmap_get(map, (struct hmap_key) {.ss = z + 1});
if (!link) return 0;
nlayer = link->value.p;
switch (dir) {
case ADJ_NORTH:
return bottom_cells(nlayer);
case ADJ_EAST:
return left_cells(nlayer);
case ADJ_SOUTH:
return top_cells(nlayer);
case ADJ_WEST:
return right_cells(nlayer);
}
return count;
} else if (pos->x < 0 || pos->x >= 5 || pos->y < 0 || pos->y >= 5) {
link = hmap_get(map, (struct hmap_key) {.ss = z - 1});
if (!link) return 0;
nlayer = link->value.p;
if (pos->x < 0) {
return nlayer->cells[2][1] == '#';
} else if (pos->x >= 5) {
return nlayer->cells[2][3] == '#';
} else if (pos->y < 0) {
return nlayer->cells[1][2] == '#';
} else if (pos->y >= 5) {
return nlayer->cells[3][2] == '#';
}
} else {
return layer->cells[pos->y][pos->x] == '#';
}
assert(0);
}
static void
step(struct hmap *map)
{
struct hmap_iter iter;
struct hmap_link **linkp;
struct hmap_link *link;
struct vec2i pos, npos;
ssize_t z, minz, maxz;
struct layer *layer;
size_t i, count;
char *cell;
minz = maxz = 0;
for (HMAP_ITER(map, iter)) {
layer = iter.link->value._p;
if (memchr(layer->cells, '#', 5 * 5)) {
minz = MIN(minz, iter.link->key.ss);
maxz = MAX(maxz, iter.link->key.ss);
}
}
minz -= 1;
maxz += 1;
for (z = minz; z <= maxz; z++) {
linkp = hmap_link_pos(map,
(struct hmap_key) {.ss = z});
if (!*linkp) {
layer = malloc(sizeof(struct layer));
memset(layer->cells, '.', 5 * 5);
*linkp = hmap_link_alloc(map,
(struct hmap_key) {.ss = z},
(struct hmap_val) {.p = layer}, NULL);
} else {
layer = (*linkp)->value._p;
}
for (pos.y = 0; pos.y < 5; pos.y++) {
for (pos.x = 0; pos.x < 5; pos.x++) {
count = 0;
for (i = 0; i < 4; i++) {
vec2i_add(&npos, &pos, &adj[i]);
count += cell_count(map,
layer, &npos, i, z);
}
layer->adj[pos.y][pos.x] = (uint8_t) count;
}
}
}
for (z = minz; z <= maxz; z++) {
for (pos.y = 0; pos.y < 5; pos.y++) {
for (pos.x = 0; pos.x < 5; pos.x++) {
link = hmap_get(map,
(struct hmap_key) {.ss = z});
layer = link->value._p;
cell = &layer->cells[pos.y][pos.x];
count = layer->adj[pos.y][pos.x];
if (*cell == '#' && count != 1) {
*cell = '.';
} else if (*cell == '.' && (count == 1 || count == 2)) {
*cell = '#';
}
}
}
}
}
void
part2(void)
{
struct hmap_iter iter;
struct hmap map;
size_t i, answer;
hmap_init(&map, 32, ssizet_hmap_hash, ssizet_hmap_keycmp,
&stdlib_strict_heap_allocator);
load_map(&map);
for (i = 0; i < 200; i++) {
step(&map);
aoc_debug("-- MIN %lu --\n\n", i);
print_layers(&map, -5, 5);
}
answer = map_count(&map);
aoc.answer = aprintf("%lu", answer);
aoc.solution = "1985";
for (HMAP_ITER(&map, iter))
free(iter.link->value._p);
hmap_deinit(&map);
}
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