#include <ctype.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aocdailies.h"
#include "aocutils.h"
#if 0
/* === aocYYYYDD =======================================================
===================================================================== */
void aocYYYYDD(char *data, size_t len) {
(void)len; // unused arguments
(void)data;
}
#endif
/* === aoc202511 =======================================================
===================================================================== */
void aoc202511(char *data, size_t len) {
(void)len; // unused arguments
(void)data;
}
/* === aoc202510 =======================================================
===================================================================== */
void aoc202510(char *data, size_t len) {
(void)len; // unused arguments
(void)data;
}
/* === aoc202509 =======================================================
===================================================================== */
struct iCoords {
int row, col;
};
void aoc202509(char *data, size_t len) {
(void)len; // unused argument
struct iCoords p[512] = {0};
char *err = data;
int k = 0;
while (*err) {
p[k].row = strtol(err, &err, 10);
if (*err != ',') break;
err++;
p[k++].col = strtol(err, &err, 10);
}
long long max_area = 0;
for (int i = 0; i < k; i++) {
for (int j = i + 1; j < k; j++) {
long long area = (abs(p[i].col - p[j].col) + 1LL)
* (abs(p[i].row - p[j].row) + 1LL);
if (area > max_area) max_area = area;
}
}
printf("P1: %lld\n", max_area);
}
/* === aoc202508 =======================================================
===================================================================== */
void aoc202508(char *data, size_t len) {
(void)data; // unused argument
(void)len; // unused argument
}
/* === aoc202507 =======================================================
===================================================================== */
static unsigned tachyon_splits(struct RectangularMap *rm) {
unsigned count = 0;
for (int row = 0; row < rm->rows; row++) {
for (int col = 0; col < rm->cols; col++) {
char cc = RMcharat(rm, col, row);
if ((cc == 'S') || (cc == '|')) {
char *pc = RMcharptr(rm, col, row+1);
if (pc == NULL) continue;
if (*pc == '.') {
*pc = '|';
} else if (*pc == '^') {
*(pc - 1) = *(pc + 1) = '|';
count++;
} else if (*pc == '|') {
/* do nothing */
} else {
/* do nothing */
}
}
}
}
return count;
}
void aoc202507(char *data, size_t len) {
(void)len; // unused argument
struct RectangularMap rm[1] = {0};
while (*data) {
char *data2 = data;
while (*data != '\n') data++;
*data = 0; // erase newline
RMaddline(rm + 0, data2);
*data++ = '\n'; // unerase newline (obviously!) and skip it
}
unsigned part1 = tachyon_splits(rm);
printf("P1: %u\n", part1);
RMfree(rm);
}
/* === aoc202506 =======================================================
===================================================================== */
static long long unsigned add2506(long long unsigned v[4][1024], int lin, int col) {
long long unsigned sum = 0;
for (int k = 0; k < lin; k++) sum += v[k][col];
return sum;
}
static long long unsigned mul2506(long long unsigned v[4][1024], int lin, int col) {
long long unsigned sum = 1;
for (int k = 0; k < lin; k++) sum *= v[k][col];
return sum;
}
static long long unsigned input_202506[4][1024];
void aoc202506(char *data, size_t len) {
(void)len; // unused argument
char *X;
for (;;) {
X = strchr(data, '\n');
if (!X) break;
*X = 'X';
}
int lin = 0, col;
char *err = data;
for (;;) { // for each line
col = 0;
for (;;) { // for each number
while (isspace(*err)) err++;
long long unsigned tmp = strtoull(err, &err, 10);
if ((*err == 'X') && (tmp == 0)) { err++; break; }
input_202506[lin][col++] = tmp;
}
lin++;
printf("got line %d with %d columns\n", lin, col);
if ((*err == '+') || (*err == '*')) break;
}
printf("from %llu to %llu\n", input_202506[0][0], input_202506[lin-1][col-1]);
col = 0;
while (isspace(*err)) err++;
long long unsigned sum = 0;
for (;;) {
switch (*err) {
default: /* does not happen! */ break;
case 'X': break;
case '+': sum += add2506(input_202506, lin, col); break;
case '*': sum += mul2506(input_202506, lin, col); break;
}
if (*err == 'X') break;
col++;
err++;
while (isspace(*err)) err++;
}
printf("part 1: %llu\n", sum);
}
/* === aoc202505 =======================================================
===================================================================== */
struct Range {
long long unsigned lo, hi;
};
static int ascending(const void *a, const void *b) {
const struct Range *aa = a, *bb = b;
if (aa->lo < bb->lo) return -1;
if (aa->lo > bb->lo) return 1;
return 0;
}
void aoc202505(char *data, size_t len) {
(void)len; // unused argument
struct Range r[200] = {0};
size_t nr = 0;
char *err;
for (;;) {
// read ranges
char *minus = strchr(data, '-');
if (!minus) break;
*minus = 0;
r[nr].lo = strtoull(data, &err, 10);
*minus++ = '-';
char *enter = strchr(minus, '\n');
*enter = 0;
r[nr++].hi = strtoull(minus, &err, 10);
*enter++ = '\n';
data = enter;
}
unsigned fresh = 0;
for (;;) {
// read and process single entries
long long unsigned item = strtoull(data, &err, 10);
if (err[0] != '\n') break;
data = err + 1;
for (size_t k = 0; k < nr; k++) {
if ((r[k].lo <= item) && (item <= r[k].hi)) {
fresh++;
break;
}
}
}
printf("There are %u fresh items.\n", fresh);
qsort(r, nr, sizeof *r, ascending);
#if 0
for (;;) {
int mergecount = 0;
for (size_t k = 1; k < nr, k++) {
for (size_t kk = 0; kk < k; kk++) {
mergecount += merge(r, kk, k) {
mergecount++;
nr--;
}
}
}
if (mergecount == 0) break;
}
#endif
}
/* === aoc202504 =======================================================
===================================================================== */
static unsigned evolve(struct RectangularMap *rm, unsigned src) {
unsigned changes = 0;
unsigned dst = 1 - src;
for (int row = 0; row < rm->rows; row++) {
for (int col = 0; col < rm->cols; col++) {
char cc = RMcharat(rm + src, col, row);
char *destin = RMcharptr(rm + dst, col, row);
if (cc == '@') {
unsigned nearby = 0;
for (int deltarow = -1; deltarow <= 1; deltarow++) {
for (int deltacol = -1; deltacol <= 1; deltacol++) {
nearby += (RMcharat(rm + src, col+deltacol,
row+deltarow) == '@');
}
}
nearby -= 1; // remove self
if (nearby < 4) {
*destin = '.';
changes++;
} else {
*destin = '@';
}
} else if (cc != 0) {
*destin = '.';
} else {
*destin = 0; // shouldn't happen, except beyond borders
}
}
}
return changes;
}
void aoc202504(char *data, size_t len) {
(void)len; // unused argument
struct RectangularMap rm[2] = {0};
while (*data) { // copy from data to rms
char *data2 = data;
while (*data != '\n') data++;
*data = 0; // erase newline
RMaddline(rm + 0, data2);
RMaddline(rm + 1, data2); // set both rm's to the same thing
*data++ = '\n'; // unerase newline (obviously!) and skip it
}
unsigned part1 = evolve(rm, 0); // evolve from rm[0] to rm[1]
unsigned part2 = part1, src = 1;
for (;;) {
unsigned tmp = evolve(rm, src); // keep evolving
if (tmp == 0) break; // STOP // back and forth
src = 1 - src; // between rm[1] and rm[0]
part2 += tmp; // add changes from this round
}
printf("P1: %u; P2: %u\n", part1, part2);
RMfree(rm);
RMfree(rm + 1);
}
/* === aoc202503 =======================================================
===================================================================== */
static long long unsigned maxj(const unsigned char *b, unsigned blen, unsigned nlen) {
if (nlen == 0) return 0;
const unsigned char *newb = b + 1;
unsigned newlen = blen - 1;
unsigned localmax = 0;
for (unsigned k = 0; k < blen - nlen + 1; k++) {
if (b[k] > localmax) {
localmax = b[k];
newb = b + k + 1;
newlen = blen - k - 1;
}
}
return localmax*upow(10, nlen - 1) + maxj(newb, newlen, nlen - 1);
}
void aoc202503(char *data, size_t len) {
(void)len; // unused argument
long long unsigned part1 = 0, part2 = 0;
char *p = data;
for (;;) {
char *pp = strchr(p, '\n');
if (pp == NULL) break;
unsigned char bank[256] = {0};
unsigned banklen;
for (banklen = 0; banklen < (unsigned)(pp - p); banklen++) {
bank[banklen] = (unsigned)p[banklen] - '0';
}
part1 += maxj(bank, banklen, 2);
part2 += maxj(bank, banklen, 12);
p = pp + 1;
}
printf("parts 1 and 2: %llu %llu\n", part1, part2);
}
/* === aoc202502 =======================================================
===================================================================== */
static int extractdata(char **data, char *p1, char *p2) {
char *d = *data;
if (*d == ',') d++; // skip ','
if (!isdigit(*d)) return 0;
while (isdigit(*d)) { *p1++ = *d++; *p1 = 0; }
if (*d != '-') { fprintf(stderr, "bad data\n"); exit(EXIT_FAILURE); }
d++; // skip '-'
while (isdigit(*d)) { *p2++ = *d++; *p2 = 0; }
*data = d;
return 1;
}
static int prepeat(int n, long long unsigned v) {
char tmp[42];
int len = sprintf(tmp, "%llu", v);
if (len % n) return 0;
if (len < 2*n) return 0;
for (int k = 0; k+n < len; k++) {
if (tmp[k] != tmp[k+n]) return 0;
}
return 1;
}
static long long unsigned suminvalid2(const char *start, const char *finis) {
long long unsigned retval = 0;
long long unsigned pstart = 0, pfinis = 0;
int k = 0;
while (start[k]) {
pstart *= 10; pstart += (unsigned)start[k] - '0';
k++;
}
k = 0;
while (finis[k]) {
pfinis *= 10; pfinis += (unsigned)finis[k] - '0';
k++;
}
for (long long unsigned kk = pstart; kk <= pfinis; kk++) {
if (prepeat(1, kk)) retval += kk;
else if (prepeat(2, kk)) retval += kk;
else if (prepeat(3, kk)) retval += kk;
else if (prepeat(4, kk)) retval += kk;
else if (prepeat(5, kk)) retval += kk;
else if (prepeat(6, kk)) retval += kk;
else if (prepeat(7, kk)) retval += kk;
else if (prepeat(8, kk)) retval += kk;
else if (prepeat(9, kk)) retval += kk;
}
return retval;
}
static long long unsigned suminvalid(const char *start, const char *finis) {
long long unsigned pstart = 0, pfinis = 0;
int k = 0;
while (start[k]) {
pstart *= 10; pstart += (unsigned)start[k] - '0';
pfinis *= 10; pfinis += (unsigned)finis[k] - '0';
k++;
}
long long unsigned lo = pstart / upow(10, (unsigned)(k/2));
long long unsigned hi = pfinis / upow(10, (unsigned)(k/2));
long long unsigned retval = 0;
for (long long unsigned kk = lo; kk <= hi; kk++) {
long long unsigned val = kk*upow(10, (unsigned)(k/2)) + kk;
if ((pstart <= val) && (val <= pfinis)) retval += val;
}
return retval;
}
void aoc202502(char *data, size_t len) {
(void)len; // unused argument
long long unsigned part1 = 0;
long long unsigned part2 = 0;
char start[42], finis[42];
while (extractdata(&data, start, finis)) {
int lenstart = strlen(start);
int lenfinis = strlen(finis);
part2 += suminvalid2(start, finis);
if (lenstart != lenfinis) {
char tmp[42];
if (lenfinis % 2) {
sprintf(tmp, "%llu", upow(10, (unsigned)lenstart) - 1);
part1 += suminvalid(start, tmp);
} else {
sprintf(tmp, "%llu", upow(10, (unsigned)lenstart));
part1 += suminvalid(tmp, finis);
}
} else {
if (lenstart % 2) {
part1 += 0;
} else {
part1 += suminvalid(start, finis);
}
}
}
printf("parts 1 and 2: %llu %llu\n", part1, part2);
}
/* === aoc202501 =======================================================
===================================================================== */
static int zeroaccum(int start, char d, int v, int *p1, int *p2) {
int direction;
switch (d) {
default: fprintf(stderr, "Invalid letter: %c\n", d);
exit(EXIT_FAILURE);
case 'R': direction = 1;
break;
case 'L': direction = -1;
break;
}
while (v--) {
start += direction;
if (start == -1) start = 99;
if (start == 100) start = 0;
if (start == 0) *p2 += 1;
}
if (start == 0) *p1 += 1;
return start;
}
void aoc202501(char *data, size_t len) {
(void)len; // unused argument
int pos = 50;
int part1 = 0, part2 = 0;
char dir; int value;
while (*data) {
dir = *data++;
value = 0;
while (isdigit(*data)) {
value *= 10;
value += *data - '0';
data++;
}
while (isspace(*data)) data++; // skip whitespace
pos = zeroaccum(pos, dir, value, &part1, &part2);
}
// part1
printf("password for part1 is %d\n", part1);
// part2
printf("password for part2 is %d\n", part2);
}