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advent-of-code/2021/day18/aoc-c.c

433 lines
10 KiB
C

/* aoc-c.c: Advent of Code 2021, day 18 parts 1 & 2
*
* Copyright (C) 2021 Bruno Raoult ("br")
* Licensed under the GNU General Public License v3.0 or later.
* Some rights reserved. See COPYING.
*
* You should have received a copy of the GNU General Public License along with this
* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
*
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "pool.h"
#include "debug.h"
#include "bits.h"
#include "list.h"
#define POISON_VALUE -232323
#define POISON_DEPTH 121212;
#define PARENT 0
#define LEFT 1
#define RIGHT 2
static pool_t *pool_nodes;
#define MAX_LINES 128
static char *lines[MAX_LINES];
static int nlines;
typedef struct node {
s64 val;
struct node *tree[3]; /* parent, left, right */
struct list_head leaf_list; /* head is tree root */
u32 depth;
} node_t;
/* print leaves list
*/
static void leaves_print(node_t *root)
{
node_t *list_cur;
log_i(2, "leaves:");
list_for_each_entry(list_cur, &root->leaf_list, leaf_list) {
log_i(2, " %d", list_cur->val);
}
log_i(2, "\n");
}
/* print node tree
*/
static void node_print(node_t *node)
{
if (!node->depth)
log_f(1, "");
if (!node->tree[LEFT]) { /* leaf */
log(1, "%ld", node->val);
} else {
log(1, "[");
node_print(node->tree[LEFT]);
log(1, ",");
node_print(node->tree[RIGHT]);
log(1, "]");
}
if (!node->depth) {
log(1, "\n");
leaves_print(node);
}
}
static inline node_t *node_get()
{
node_t *node = pool_get(pool_nodes);
node->depth = POISON_DEPTH;
node->val = POISON_VALUE;
node->tree[LEFT] = NULL;
node->tree[RIGHT] = NULL;
node->tree[PARENT] = NULL;
INIT_LIST_HEAD(&node->leaf_list);
return node;
}
/* split_node - split first node with value >= 10
* return: 1: finished
*/
static int node_split(node_t *node)
{
int depth = node->depth;
static node_t *root;
if (depth == 0)
root = node;
//if (node->depth == 0)
log_f(2, "entering node %p: val=%d left=%p right=%p\n", node, node->val,
node->tree[LEFT], node->tree[RIGHT]);
if (node->tree[LEFT]) {
if (node_split(node->tree[LEFT]) || node_split(node->tree[RIGHT]))
return 1;
} else {
if (node->val >= 10) { /* eligible leaf */
//node_t *leaf_left = list_prev_entry(node, leaf_list);
node_t *left, *right;
log_i(2, "splitting [%ld,%ld]\n", node->val);
/* create and populate new nodes */
left = node_get();
left->depth = node->depth + 1;
left->val = node->val / 2;
right = node_get();
right->depth = node->depth + 1;
right->val = (node->val + 1) / 2;
node->tree[LEFT] = left;
node->tree[RIGHT] = right;
node->val = POISON_VALUE;
/* add new nodes in leaves list, remove current one */
list_add(&node->tree[RIGHT]->leaf_list, &node->leaf_list);
list_add(&node->tree[LEFT]->leaf_list, &node->leaf_list);
list_del(&node->leaf_list);
log_i(2, "after split: \n\t");
node_print(root);
return 1;
}
}
if (node->depth == 0) {
log_f(2, "return:\n\t");
node_print(node);
}
return 0;
}
/* explode node - explode first node with level == 4
* return: 1: finished
*/
static int node_explode(node_t *node)
{
int depth = node->depth;
static node_t *root;
if (depth == 0) {
root = node;
log_f(2, "entering node %p: val=%d left=%p right=%p\n", node, node->val,
node->tree[LEFT], node->tree[RIGHT]);
}
if (depth == 4) {
node_t *left = node->tree[LEFT], *right = node->tree[RIGHT];
node_t *tmp;
//struct list_head *tmp;
/* skip leaves */
if (!left)
return 0;
log_i(2, "exploding [%ld,%ld]\n", left->val, right->val);
//log_i(2, "zobu: ");
//node_print(root);
/* increment left leaf */
if (!list_is_first(&left->leaf_list, &root->leaf_list)) {
node_t *tmpnode = list_prev_entry(left, leaf_list);
tmpnode->val += left->val;
}
/* increment right leaf */
if (!list_is_last(&right->leaf_list, &root->leaf_list)) {
node_t *tmpnode = list_next_entry(right, leaf_list);
tmpnode->val += right->val;
}
//log_i(2, "zobi: ");
//node_print(root);
/* remove leaves from list, and add current one */
//tmp = list_entry(left, node_t, leaf_list);
node->val = 0;
list_add(&node->leaf_list, &left->leaf_list);
//log_i(2, "zoba: n=%p l=%p) ", &node->leaf_list, &left->leaf_list);
//node_print(root);
//list_del(&left->leaf_list);
//list_del(left->leaf_list.prev);
//list_del(&node->leaf_list->prev);
//tmp = list_prev_entry(node, leaf_list);
//log_i(2, "zoby: n=%p l=%p) ", &node->leaf_list, &left->leaf_list);
list_del(&left->leaf_list);
//node->leaf_list.prev;
//log_i(2, "zobe: ");
//node_print(root);
pool_add(pool_nodes, left);
list_del(&right->leaf_list);
//log_i(2, "zobo: ");
//node_print(root);
pool_add(pool_nodes, right);
/* remove childs links */
node->tree[LEFT] = NULL;
node->tree[RIGHT] = NULL;
//log_i(2, "after reduce: ");
//node_print(root);
return 1;
} else {
if (node->tree[LEFT]) {
if (node_explode(node->tree[LEFT]) || node_explode(node->tree[RIGHT]))
return 1;
}
}
return 0;
}
static node_t *node_reduce(node_t *node)
{
//log_f(2, "");
//node_explode(node);
//node_explode(node);
//return node;
while (1) {
log_f(2, "\t");
node_print(node);
if (node_explode(node))
continue;
if (node_split(node))
continue;
break;
}
return node;
}
/* promote/demode node
*/
static node_t *node_promote(node_t *node, int promote)
{
node->depth += promote;
if (node->tree[LEFT]) {
node_promote(node->tree[LEFT], promote);
node_promote(node->tree[RIGHT], promote);
}
return node;
}
/* add 2 nodes
*/
static node_t *node_add(node_t *n1, node_t *n2)
{
node_t *head = pool_get(pool_nodes);
log_f(2, "\n");
node_print(n1);
node_print(n2);
head->depth = 0;
INIT_LIST_HEAD(&head->leaf_list);
/* create new tree from the two
*/
head->tree[LEFT] = node_promote(n1, 1);
head->tree[RIGHT] = node_promote(n2, 1);
n1->tree[PARENT] = head;
n2->tree[PARENT] = head;
/* link leaves
*/
//head->leaf_list = n1->leaf_list;
list_splice_tail(&n1->leaf_list, &head->leaf_list);
list_splice_tail(&n2->leaf_list, &head->leaf_list);
//node_print(head);
return head;
}
/* read node, from '[' to corresponding ']'
*/
static node_t *node_read(char **p, int depth)//, node_t *parent)
{
static node_t *root;
node_t *node = node_get();
node->depth = depth;
if (!depth) /* root node */
root = node;
//log_f(2, "str=%s depth=%d\n", *p, depth);
switch (**p) {
case '[':
(*p)++;
node->tree[LEFT] = node_read(p, depth+1);
node->tree[LEFT]->tree[PARENT] = node;
//log_i(2, "comma = %c\n", **p);
(*p)++;
node->tree[RIGHT] = node_read(p, depth+1);
node->tree[RIGHT]->tree[PARENT] = node;
//log_i(2, "closing = %c\n", **p);
break;
default: /* number */
//log_i(2, "number = %c\n", **p);
node->val = **p - '0';
list_add_tail(&node->leaf_list, &root->leaf_list);
}
(*p)++;
return node;
}
/* read line, create a tree
*/
static node_t *read_line()
{
node_t *head = NULL;
size_t alloc = 0;
char *buf, *p;
ssize_t buflen;
if ((buflen = getline(&buf, &alloc, stdin)) > 0) {
p = buf;
buf[--buflen] = 0;
head = node_read(&p, 0);
}
free(buf);
//node_print(head);
return head;
}
/* read input
*/
static int read_lines()
{
size_t alloc = 0;
ssize_t buflen;
while ((buflen = getline(&lines[nlines], &alloc, stdin)) > 0) {
lines[nlines][--buflen] = 0;
nlines++;
}
return nlines;
}
/* free lines memory
*/
static void free_lines()
{
for (int i = 0; i < nlines; ++i)
free(lines[i]);
}
static s64 node_magnitude(node_t *node)
{
if (!node->tree[LEFT])
return node->val;
return 3 * node_magnitude(node->tree[LEFT]) +
2 * node_magnitude(node->tree[RIGHT]);
}
static s64 part1()
{
node_t *head = NULL, *next = NULL;
s64 res = 1;
head = node_read(lines + 0, 0);
for (int i = 1; i < nlines; ++i) {
next = node_read(lines + i, 0);
head = node_reduce(node_add(head, next));
}
node_print(head);
return node_magnitude(head);
}
static s64 part2()
{
s64 res = 2;
return res;
}
static int usage(char *prg)
{
fprintf(stderr, "Usage: %s [-d debug_level] [-p part]\n", prg);
return 1;
}
int main(int ac, char **av)
{
int opt, part = 1;
while ((opt = getopt(ac, av, "d:p:")) != -1) {
switch (opt) {
case 'd':
debug_level_set(atoi(optarg));
break;
case 'p': /* 1 or 2 */
part = atoi(optarg);
if (part < 1 || part > 2)
return usage(*av);
break;
default:
return usage(*av);
}
}
if (optind < ac)
return usage(*av);
if (!(pool_nodes = pool_create("nodes", 1024, sizeof(node_t))))
exit(1);
read_lines();
printf("%s : res=%ld\n", *av, part == 1? part1(): part2());
exit(0);
node_t *n1, *n2, *n3, *n4;
n1 = read_line();
n2 = read_line();
//node_print(n1);
//node_print(n2);
n3 = node_add(n1, n2);
//node_print(n3);
n4 = node_reduce(n3);
node_print(n4);
free_lines();
exit(0);
//node_print(n1);
//node_print(n2);
n3 = node_add(n1, n2);
node_print(n3);
printf("%s : res=%ld\n", *av, part == 1? part1(): part2());
exit (0);
}