120 lines
2.6 KiB
C
120 lines
2.6 KiB
C
/* aoc-c: Advent of Code 2021, day 6 parts 1 & 2
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*
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* Copyright (C) 2021 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 <string.h>
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#include <malloc.h>
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#include "debug.h"
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#include "bits.h"
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#define NFISH 9
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static u64 fish[NFISH];
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inline static u64 fish_count()
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{
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u64 nfish = 0;
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for (int i = 0; i < NFISH; ++i)
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nfish += fish[i];
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return nfish;
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}
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#ifdef DEBUG
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static void print_fish()
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{
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int i = 0;
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printf("fish: %lu\n", fish_count());
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for (i = 0; i < NFISH; ++i)
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printf("%10d", i);
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printf("\n");
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for (i = 0; i < NFISH; ++i)
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printf("%10lu", fish[i]);
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printf("\n");
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}
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#endif
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static u64 read_fish()
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{
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char *buf, *token;
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size_t alloc = 0;
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u64 nfish = 0;
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if (getline(&buf, &alloc, stdin) < 0)
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return -1;
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token = strtok(buf, ",\n");
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while (token) {
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fish[atoi(token)]++;
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nfish++;
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token = strtok(NULL, ",\n");
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}
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free(buf);
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return nfish;
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}
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static void doit(int part, int iter)
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{
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u64 toadd;
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if (!iter)
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iter = part == 1 ? 80: 256;
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for (; iter; --iter) {
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toadd = fish[0];
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for (int i = 1; i < NFISH; ++i)
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fish[i - 1] = fish[i];
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fish[NFISH - 1] = toadd;
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fish[6] += toadd;
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}
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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] [-i iter]\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, iter = 0;
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u32 exercise = 1;
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while ((opt = getopt(ac, av, "d:p:i:")) != -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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exercise = atoi(optarg);
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if (exercise < 1 || exercise > 2)
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return usage(*av);
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break;
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case 'i': /* 1 or 2 */
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iter = atoi(optarg);
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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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read_fish();
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doit(exercise, iter);
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printf ("%s : res=%lu\n", *av, fish_count());
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exit (0);
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}
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