bruno/advent-of-code
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

2020/19 (C): cleanup code

Browse Source
This commit is contained in:
Bruno Raoult
2022-10-27 16:14:48 +02:00
parent 74ab0ba990
commit 8df13f9713
1 changed files with 51 additions and 103 deletions
Download Patch File Download Diff File Expand all files Collapse all files

154
2020/day19/aoc-c.c
View File

@@ -39,36 +39,66 @@ static struct mesg {
} mesg[MAX_MSG];
static int nrules, nmesg;
static void printall()
static int match(struct mesg *msg, int *pos, int rule)
{
for (int i = 0; i < nrules; ++i) {
printf("rule %3d : ", i);
if (rules[i].type == CHR) {
printf("[%c]\n", rules[i].str);
continue;
struct rule *r = rules + rule;
int found = 0, postmp, recurse = 0;
if (r->type == CHR)
return rules[rule].str == msg->str[(*pos)++];
for (int side = 0; side < 2; ++side, recurse = 0, found = 0) {
if (r->sub.rule[side][0] == -1)
break;
postmp = *pos;
found = 1;
for (int sub = 0; sub < 3 && r->sub.rule[side][sub] >= 0; ++sub) {
if (*pos == msg->len)
return recurse;
recurse = r->sub.rule[side][sub] == rule;
if (!match(msg, pos, r->sub.rule[side][sub])) {
found = 0;
*pos = postmp; /* roll back */
break;
}
}
for (int j = 0; j < 3 && rules[i].sub.rule[0][j] != -1; ++j)
printf("%d ", rules[i].sub.rule[0][j]);
for (int j = 0; j < 3 && rules[i].sub.rule[1][j] != -1; ++j)
printf("%s%d ", j? "": "| ", rules[i].sub.rule[1][j]);
printf("\n");
}
for (int i = 0; i < nmesg; ++i) {
printf("%3d: len=%d %s\n", i, mesg[i].len, mesg[i].str);
if (found)
break;
}
return found;
}
static long part1()
{
int ret = 0;
for (int msg = 0, pos = 0; msg < nmesg; ++msg, pos = 0)
if (match(mesg + msg, &pos, 0))
ret += pos == mesg[msg].len;
return ret;
}
static long part2()
{
static const struct subrule new[2] = {
{{{42, -1, -1}, {42, 8, -1}}},
{{{42, 31, -1}, {42, 11, 31}}}
};
rules[8].sub = new[0];
rules[11].sub = new[1];
return part1();
}
/**
* parse - parse input.
*/
static void parse()
{
size_t alloc;
ssize_t len;
char *buf = NULL, *tok;
int rule;
while ((len = getline(&buf, &alloc, stdin)) > 0) {
int or = 0, sub = 0;
int set = 0, sub = 0;
buf[--len] = 0;
if (len == 0)
@@ -87,104 +117,23 @@ static void parse()
case 'b':
rules[rule].type = CHR;
rules[rule].str = *tok;
goto nextline;
break;
case '|': /* second ruleset */
or++;
set++;
sub = 0;
break;
default:
rules[rule].type = SUB;
rules[rule].sub.rule[or][sub] = atoi(tok);
rules[rule].sub.rule[set][sub] = atoi(tok);
sub++;
break;
}
}
}
nextline: ;
}
free(buf);
}
static int match(struct mesg *msg, int *pos, int rule, int depth)
{
struct rule *r = rules+rule;
int found = 0, postmp, recurse = 0;
char *space = " ";
log_f(3, "%.*sstr=%s pos=%d rule=%d\n", depth * 2, space, msg->str,
*pos, rule);
if (r->type == CHR)
return rules[rule].str == msg->str[(*pos)++];
for (int side = 0; side < 2; ++side) {
if (r->sub.rule[side][0] == -1) {
found = 0;
break;
}
postmp = *pos;
recurse = 0;
found = 1;
for (int sub = 0; sub < 3 && r->sub.rule[side][sub] >= 0; ++sub) {
if (*pos == msg->len)
return recurse;
if (r->sub.rule[side][sub] == rule) {
log(3, "recursing %d rule\n", rule);
recurse = 1;
}
if (!match(msg, pos, r->sub.rule[side][sub], depth + 1)) {
found = 0;
*pos = postmp;
break;
}
}
if (found)
break;
}
/* check for exact length */
if (depth == 0 && msg->str[*pos]) {
log_f(3, "pos=%d len=%d chars remaining !\n", *pos, msg->len);
found = 0;
}
log_f(3, "%.*sstr=%s pos=%d rule=%d ret=%s\n",
depth * 2, space, msg->str+*pos, *pos, rule, found? "ok": "NOK");
return found; /* not reached */
}
static long part1()
{
int ok = 0, pos;
for (int msg = 0; msg < nmesg; ++msg) {
pos = 0;
if (match(mesg + msg, &pos, 0, 0)) {
log(2, "len=%d pos=%d %s: ok\n", mesg[msg].len, pos, mesg[msg].str);
ok++;
} else {
log(2, "len=%d pos=%d %s: NOK\n", mesg[msg].len, pos, mesg[msg].str);
}
}
return ok;
}
static long part2()
{
static const struct subrule new[2] = {
{{{42, -1, -1}, {42, 8, -1}}},
{{{42, 31, -1}, {42, 11, 31}}}
};
rules[8].sub = new[0];
rules[11].sub = new[1];
int ok = 0, pos;
for (int msg = 0; msg < nmesg; ++msg) {
pos = 0;
if (match(mesg + msg, &pos, 0, 0)) {
log(2, "len=%d pos=%d %s: ok\n", mesg[msg].len, pos, mesg[msg].str);
ok++;
} else {
log(2, "len=%d pos=%d %s: NOK\n", mesg[msg].len, pos, mesg[msg].str);
}
}
return ok;
}
static int usage(char *prg)
{
fprintf(stderr, "Usage: %s [-d debug_level] [-p part]\n", prg);
@@ -212,6 +161,5 @@ int main(ac, av)
parse();
printf("%s : res=%ld\n", *av, part == 1? part1(): part2());
//printall();
exit (0);
}