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C: 2022/Day 3 final cleanup + more comments

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This commit is contained in:
Bruno Raoult
2022-12-08 08:19:57 +01:00
parent b7c0b1fa01
commit bc2b2ac726
1 changed files with 25 additions and 24 deletions
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49
2022/day03/aoc-c.c
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@@ -37,22 +37,21 @@ static void map_populate(char *ex, char *p, int len)
SET_MAP(ex, p[len - 1]);
}
/* match map1 and map2 maps. If dest is NULL, return first match,
/* match map with items list. If dest is NULL, return first match,
* otherwise populate dest with matching chars.
* TODO: replace map2 with the initial items string, this would avoid
* a loop.
*/
static int map_match(char *dest, char *map1, char *map2)
static int map_match(char *dest, char *map, char *items, int ilen)
{
if (dest)
map_init(dest);
for (int i = 0; i < NCHARS; ++i) {
if (map1[i] && map2[i]) {
for (int i = 0; i < ilen; ++i) {
int pos = CHAR2POS(items[i]);
if (map[pos]) { /* already exists */
if (dest)
dest[i] = 1; /* fill dest array */
dest[pos] = 1; /* fill dest array */
else
return i; /* ont match only */
return pos + 1; /* one match only: return prio */
}
}
return -1; /* unused if dest != NULL */
@@ -63,26 +62,28 @@ static int parse(int part)
size_t alloc = 0;
char *buf = NULL;
ssize_t buflen;
int line = 0, res = 0, half;
char map[3][NCHARS], ctmp[NCHARS];
int line = 0, res = 0;
char map[2][NCHARS];
while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
buf[--buflen] = 0;
if (part == 1) {
half = buflen / 2;
/* populate c1 */
map_populate(map[0], buf, half);
map_populate(map[1], buf + half, half);
/* calculate part 1 */
res += map_match(NULL, map[0], map[1]) + 1;
} else {
/* populate c2 */
map_populate(map[line % 3], buf, buflen);
if ((++line % 3))
continue;
/* calculate part 2 */
map_match(ctmp, map[0], map[1]);
res += map_match(NULL, ctmp, map[2]) + 1;
int half = buflen / 2;
map_populate(*map, buf, half); /* populate and calculate */
res += map_match(NULL, *map, buf + half, half);
continue;
}
/* Part 2 here */
switch (++line % 3) { /* group lines by 3 */
case 1: /* line 1: populate *map */
map_populate(*map, buf, buflen);
break;
case 2: /* line 2: merge #1 into map[1] */
map_match(*(map + 1), *map, buf, buflen);
break;
case 0: /* line 3: final merge & calc */
res += map_match(NULL, *(map + 1), buf, buflen);
break;
}
}
free(buf);