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#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SIDE 99U
int
main(int argc, char **argv) {
char *buf = NULL;
size_t buflen = 0;
ssize_t n;
FILE *f;
char grid[SIDE][SIDE] = {0};
if (argc != 2) {
fprintf(stderr, "usage: %s input\n", argv[0]);
return 1;
}
f = fopen(argv[1], "r");
if (f == NULL) {
perror(argv[1]);
return 1;
}
size_t row = 0;
while ((n = getline(&buf, &buflen, f)) != -1) {
if (buf[n - 1] == '\n') {
buf[n - 1] = '\0';
n--;
}
assert(n == SIDE);
assert(row < SIDE);
memcpy(grid[row++], buf, n);
}
free(buf);
fclose(f);
int total = 0;
for (size_t i = 0; i < SIDE; i++) {
for (size_t j = 0; j < SIDE; j++) {
char me = grid[i][j];
char visl, visr, visu, visd;
visl = visr = visu = visd = 1;
/* wow, this is awful */
for (size_t k = 0; k < i; k++) {
if (grid[k][j] >= me) {
visu = 0;
break;
}
}
if (visu)
goto visible; /* an optimisation! */
for (size_t k = i + 1; k < SIDE; k++) {
if (grid[k][j] >= me) {
visd = 0;
break;
}
}
if (visd)
goto visible;
for (size_t l = 0; l < j; l++) {
if (grid[i][l] >= me) {
visl = 0;
break;
}
}
if (visl)
goto visible;
for (size_t l = j + 1; l < SIDE; l++) {
if (grid[i][l] >= me) {
visr = 0;
break;
}
}
if (visu || visd || visl || visr) {
visible:
total++;
}
}
}
printf("Part A: %d\n", total);
int max = 0;
for (size_t i = 0; i < SIDE; i++) {
for (size_t j = 0; j < SIDE; j++) {
total = 0;
char me = grid[i][j];
int visl, visr, visu, visd;
visl = visr = visu = visd = 0;
/* lazy but it works */
for (int k = i - 1; k >= 0; k--) {
visu++;
if (grid[k][j] >= me)
break;
}
if (visu == 0)
continue;
for (size_t k = i + 1; k < SIDE; k++) {
visd++;
if (grid[k][j] >= me)
break;
}
if (visd == 0)
continue;
for (int l = j - 1; l >= 0; l--) {
visl++;
if (grid[i][l] >= me)
break;
}
if (visl == 0)
continue;
for (size_t l = j + 1; l < SIDE; l++) {
visr++;
if (grid[i][l] >= me)
break;
}
total = visu * visd * visl * visr;
if (total > max) {
/*fprintf(stderr, "%d -> %d at [%lu,%lu] = %c sees [%d,%d,%d,%d]\n",
* max, total, i, j, me, visu, visr, visd, visl);*/
max = total;
}
}
}
printf("Part B: %d\n", max);
return 0;
}
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