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#include <algds/str.h>
#include <algds/vec.h>
StringVector readmap() {
StringVector map;
StringVector_init(&map);
while (1) {
char *l = fgetline(stdin);
if (!l) {
return map;
}
char *nl = str_strip(l);
free(l);
l = nl;
if (strlen(l) == 0) {
return map;
}
StringVector_push_back(&map, l);
}
return map;
}
char map_read(StringVector *map, int x, int y) {
int height = StringVector_len(map);
if (height == 0) {
return '\0';
}
int width = strlen(*StringVector_ref(map, 0));
if (x >= width || x < 0) {
return '\0';
}
if (y >= height || y < 0) {
return '\0';
}
return (*StringVector_ref(map, y))[x];
}
void map_set(StringVector *map, int x, int y, char c) {
int height = StringVector_len(map);
if (height == 0) {
return;
}
int width = strlen(*StringVector_ref(map, 0));
if (x >= width || x < 0) {
return;
}
if (y >= height || y < 0) {
return;
}
((char*)*StringVector_ref(map, y))[x] = c;
}
bool is_paper(StringVector *map, int x, int y) {
char c = map_read(map, x, y);
return c == '@';
}
int count_adjacent(StringVector *map, int x, int y) {
int count = 0;
if (is_paper(map, x - 1, y - 1)) {
count++;
}
if (is_paper(map, x - 1, y)) {
count++;
}
if (is_paper(map, x, y - 1)) {
count++;
}
if (is_paper(map, x + 1, y + 1)) {
count++;
}
if (is_paper(map, x + 1, y)) {
count++;
}
if (is_paper(map, x, y + 1)) {
count++;
}
if (is_paper(map, x + 1, y - 1)) {
count++;
}
if (is_paper(map, x - 1, y + 1)) {
count++;
}
return count;
}
int iter(StringVector *map, int height, int width) {
int forked = 0;
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
if (map_read(map, x, y) != '@') {
continue;
}
if (count_adjacent(map, x, y) < 4) {
map_set(map, x, y, 'x');
forked++;
}
}
}
return forked;
}
void free_map(StringVector *map) {
for (int i = 0; i < StringVector_len(map); i++) {
free((void*)*StringVector_ref(map, i));
}
StringVector_free(map);
}
int main() {
StringVector map = readmap();
int height = StringVector_len(&map);
int width = strlen(*StringVector_ref(&map, 0));
int res = 0;
while (1) {
int n = iter(&map, height, width);
if (n > 0) {
res += n;
} else {
break;
}
}
printf("%d\n", res);
free_map(&map);
return 0;
}
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