308 lines
8.5 KiB
C
308 lines
8.5 KiB
C
/* aoc-c.c: Advent of Code 2021, day 19 parts 1 & 2
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*
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* Copyright (C) 2022 Bruno Raoult ("br")
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* Licensed under the GNU General Public License v3.0 or later.
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* Some rights reserved. See COPYING.
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*
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* You should have received a copy of the GNU General Public License along with this
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* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
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*
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* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "pool.h"
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#include "debug.h"
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#include "bits.h"
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#include "list.h"
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/*
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typedef struct beacon {
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int x, y, z;
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struct list_head list_beacons;
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} beacon_t;
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typedef struct scanner {
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struct list_head list_beacons;
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} scanner_t;
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*/
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#define MAX_SCANNERS 32 /* I know, I know... */
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#define MAX_BEACONS 32
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#define MAX_DISTANCES ((MAX_BEACONS - 1) * MAX_BEACONS)
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typedef struct beacon {
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int x, y, z; /* beacon coordinates */
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uint count; /* common scanner distance count */
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//struct list_head list_beacons;
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} beacon_t;
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typedef struct dist {
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uint dist; /* square distance */
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int b1, b2; /* beacons */
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} dist_t;
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typedef struct scanner {
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//struct list_head list_beacons;
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int nbeacons, ndists;
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beacon_t beacons[MAX_BEACONS];
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dist_t dists[MAX_DISTANCES]; /* sorted */
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} scanner_t;
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static pool_t *pool_beacon;
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static scanner_t scanners[MAX_SCANNERS];
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static int nscanners;
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static void scanners_print_dists()
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{
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dist_t *cur;
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log_f(1, "nscanners: %d\n", nscanners);
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for (int i = 0; i < nscanners; ++i) {
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log(1, "scanner %d:\n", i);
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for (int j = 0; j < scanners[i].ndists; ++j) {
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cur = &scanners[i].dists[j];
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log(1, "\t%u : %d,%d\n", cur->dist, cur->b1, cur->b2);
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}
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log(1, "\n");
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}
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}
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static void scanners_print()
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{
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beacon_t *cur;
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log_f(1, "nscanners: %d\n", nscanners);
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for (int i = 0; i < nscanners; ++i) {
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log(1, "scanner %d:\n\t", i);
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/*
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list_for_each_entry(cur, &scanners[i].list_beacons, list_beacons) {
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log(1, " %d/%d/%d", cur->x, cur->y, cur->z);
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}
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*/
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for (int j = 0; j < scanners[i].nbeacons; ++j) {
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cur = &scanners[i].beacons[j];
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log(1, " %d/%d/%d", cur->x, cur->y, cur->z);
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}
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log(1, "\n");
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}
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}
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static void merge(array, left, mid, right)
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dist_t *array;
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int left, mid, right;
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{
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dist_t temp[right - left + 1];
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int pos = 0, lpos = left, rpos = mid + 1, iter;
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while(lpos <= mid && rpos <= right) {
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if(array[lpos].dist < array[rpos].dist) {
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temp[pos++] = array[lpos++];
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}
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else {
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temp[pos++] = array[rpos++];
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}
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}
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while(lpos <= mid)
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temp[pos++] = array[lpos++];
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while(rpos <= right)
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temp[pos++] = array[rpos++];
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for(iter = 0; iter < pos; iter++) {
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array[iter+left] = temp[iter];
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}
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return;
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}
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static void mergesort(array, left, right)
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dist_t *array;
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int left, right;
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{
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int mid = (left + right) / 2;
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if(left < right) {
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mergesort(array, left, mid);
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mergesort(array, mid + 1, right);
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merge(array, left, mid, right);
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}
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}
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static int count_common_distances(scanner_t *s1, scanner_t *s2)
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{
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dist_t *d1 = s1->dists, *d2 = s2->dists;
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int cur1 = 0, cur2 = 0, i;
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uint count = 0;
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beacon_t *beacon1 = s1->beacons, *beacon2 = s2->beacons;
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/* initialize s1 and s2 beacons count
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*/
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for (i = 0; i < s1->nbeacons; ++i)
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beacon1[i].count = 0;
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for (i = 0; i < s2->nbeacons; ++i)
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beacon2[i].count = 0;
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log_f(1, "(%ld, %ld): ", s1 - scanners, s2 - scanners);
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while (cur1 < s1->ndists && cur2 < s2->ndists) {
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if (d1[cur1].dist == d2[cur2].dist) {
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log(1, " (%d,%d)=%u", cur1, cur2, d1[cur1].dist);
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++beacon1[d1[cur1].b1].count;
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++beacon1[d1[cur1].b2].count;
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++beacon2[d2[cur2].b1].count;
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++beacon2[d2[cur2].b2].count;
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++count;
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++cur1;
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++cur2;
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}
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else if (d1[cur1].dist < d2[cur2].dist) {
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++cur1;
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} else {
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++cur2;
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}
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}
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log_i(3, "\n");
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return count;
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}
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static void calc_square_distances()
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{
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scanner_t *scanner;
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beacon_t *b1, *b2;
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uint dist;
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log_f(1, "nscanners: %d\n", nscanners);
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for (int i = 0; i < nscanners; ++i) {
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scanner = scanners + i;
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for (int j = 0; j < scanner->nbeacons; ++j) {
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b1 = scanner->beacons + j;
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for (int k = j + 1; k < scanner->nbeacons; ++k) {
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scanner->dists[scanner->ndists].b1 = j;
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scanner->dists[scanner->ndists].b2 = k;
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b2 = scanner->beacons + k;
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dist = (b1->x - b2->x) * (b1->x - b2->x) +
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(b1->y - b2->y) * (b1->y - b2->y) +
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(b1->z - b2->z) * (b1->z - b2->z);
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scanner->dists[scanner->ndists].dist = dist;
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scanner->ndists++;
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log(5, "\tdist(%d/%d) = %u\n",
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j, k,
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dist);
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}
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}
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scanners_print_dists();
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mergesort(scanner->dists, 0, scanner->ndists - 1);
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}
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scanners_print_dists();
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log(1, "\n");
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}
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/* read input
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*/
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static int read_lines()
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{
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size_t alloc = 0;
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ssize_t buflen;
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char *buf = NULL;
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beacon_t *beacon;
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scanner_t *scanner = NULL;
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//int nbeacon = 0;
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while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
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//buf[--buflen] = 0;
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switch (buf[1]) {
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case '-':
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scanner = scanners + nscanners;
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log_f(2, "[%c] nscanners = %d %p/%p\n", *buf, nscanners,
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scanner, scanners);
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//INIT_LIST_HEAD(&scanner->list_beacons);
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nscanners++;
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scanner->nbeacons = 0;
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break;
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case '\0':
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log_f(2, "NULL line\n");
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break;
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default:
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//log_f(2, "[%c] beacon = %d\n", *buf, nscanners);
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//beacon = pool_get(pool_beacon);
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//list_add_tail(&beacon->list_beacons, &scanner->list_beacons);
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beacon = &scanner->beacons[scanner->nbeacons];
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sscanf(buf, "%d,%d,%d", &beacon->x, &beacon->y, &beacon->z);
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//log_f(2, "beacon %d = %d/%d/%d\n", nbeacon, beacon->x, beacon->y, beacon->z);
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scanner->nbeacons++;
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}
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}
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free(buf);
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scanners_print();
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calc_square_distances();
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for (int i = 0; i < nscanners - 1; ++i) {
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for (int j = i + 1; j < nscanners; ++j) {
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int count = count_common_distances(scanners + i, scanners + j);
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if (count >= 66) {
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log(1, "common(%d, %d) = %d\n", i, j, count);
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for (int k = 0; k < scanners[i].nbeacons; ++k) {
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beacon_t *beacon = scanners[i].beacons + k;
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if (beacon->count >= 11)
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log(1, "s1(%d, %d, %d): %d\n", beacon->x, beacon->y,
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beacon->z, beacon->count);
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}
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for (int k = 0; k < scanners[j].nbeacons; ++k) {
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beacon_t *beacon = scanners[j].beacons + k;
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if (beacon->count >= 11)
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log(1, "s2(%d, %d, %d): %d\n", beacon->x, beacon->y,
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beacon->z, beacon->count);
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}
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}
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}
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}
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return nscanners;
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}
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static s64 part1()
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{
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return 1;
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}
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static s64 part2()
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{
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return 2;
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}
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static int usage(char *prg)
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{
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fprintf(stderr, "Usage: %s [-d debug_level] [-p part]\n", prg);
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return 1;
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}
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int main(int ac, char **av)
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{
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int opt, part = 1;
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while ((opt = getopt(ac, av, "d:p:")) != -1) {
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switch (opt) {
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case 'd':
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debug_level_set(atoi(optarg));
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break;
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case 'p': /* 1 or 2 */
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part = atoi(optarg);
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if (part < 1 || part > 2)
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return usage(*av);
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break;
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default:
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return usage(*av);
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}
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}
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if (optind < ac)
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return usage(*av);
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if (!(pool_beacon = pool_create("beacons", 1024, sizeof(beacon_t))))
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exit(1);
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read_lines();
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printf("%s : res=%ld\n", *av, part == 1? part1(): part2());
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pool_destroy(pool_beacon);
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exit(0);
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}
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