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/* === aoc202408 =======================================================
Oh! another square of text!
Idea: for all points p with an antenna find all points q>p with
a corresponding frequency. For each such pair calculate the 2 antinodes
and add the resulting points (if not there already) to an array.
The answer to Part One is the number of elements in the array
TODO: I don't like my `linearize2d` thing! Thinking of a replacement
printf("p is at (C:%u, R:%u); q is at (C:%u, R:%u)\n",
TGcol(&tg, p), TGrow(&tg, p),
TGcol(&tg, q), TGrow(&tg, q));
q = strchr(q+1, *p); // next antenna of this type
}
p += 1;
}
}
#if 0
unsigned size = 1 + strchr(data, '\n') - data;
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/* === aoc202408 =======================================================
Oh! another square of text!
Idea: for all points p with an antenna find all points q>p with
a corresponding frequency. For each such pair calculate the 2 antinodes
and add the resulting points (if not there already) to an array.
The answer to Part One is the number of elements in the array
===================================================================== */
void aoc202408(char *data, size_t len) {
(void)len; // unused argument
struct TextGrid tg;
tg.data = data;
tg.cols = strchr(data, '\n') - data + 1;
tg.rows = tg.cols - 1; // rows includes the '\n'
#if 0
unsigned anti[256][2]; // locations of antinodes
unsigned nanti = 0;
#endif
char *p = data;
while (*p) {
while ((*p == '.') || (*p == '\n')) p++;
if (*p) {
// p points to an antenna
unsigned prow = TGrow(&tg, p), pcol = TGcol(&tg, p);
char *q = strchr(p+1, *p);
while (q) {
// q points to an antenna of the same type as p
unsigned qrow = TGrow(&tg, q), qcol = TGcol(&tg, q);
int deltarow = (int)qrow - (int)prow;
int deltacol = (int)qcol - (int)pcol;
printf("p is at (C:%u, R:%u); q is at (C:%u, R:%u) ... delta: (C: %d, R: %d)\n",
pcol, prow, qcol, qrow, deltacol, deltarow);
int col1 = (int)pcol - deltacol, row1 = (int)prow - deltarow;
if (TGvalid(&tg, row1, col1)) {
printf("antinode at (C:%u, R:%u)\n", col1, row1);
}
int col2 = (int)qcol + deltacol, row2 = (int)qrow + deltarow;
if (TGvalid(&tg, row2, col2)) {
printf("antinode at (C:%u, R:%u)\n", col2, row2);
}
q = strchr(q+1, *p); // next antenna of this type
}
p += 1;
}
}
#if 0
unsigned size = 1 + strchr(data, '\n') - data;
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