diff options
| -rw-r--r-- | 2020/day07.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/2020/day07.c b/2020/day07.c new file mode 100644 index 0000000..3d97d5f --- /dev/null +++ b/2020/day07.c @@ -0,0 +1,60 @@ +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +static struct Bag { + char adj[16]; + char col[16]; + struct { + int cnt; + char adj[16]; + char col[16]; + } cons[4]; +} bags[600]; +static int len; +static int compar(const void *_a, const void *_b) { + const struct Bag *a = _a; + const struct Bag *b = _b; + int ret = strcmp(a->adj, b->adj); + if (ret) return ret; + return strcmp(a->col, b->col); +} +static struct Bag *findBag(const char *adj, const char *col) { + struct Bag needle = {0}; + strcpy(needle.adj, adj); + strcpy(needle.col, col); + return bsearch(&needle, bags, len, sizeof(bags[0]), compar); +} +static bool canContain(struct Bag *bag, const char *adj, const char *col) { + for (int i = 0; i < 4; ++i) { + if (!bag->cons[i].adj[0]) break; + if (!strcmp(bag->cons[i].adj, adj) && !strcmp(bag->cons[i].col, col)) { + return true; + } + if (canContain(findBag(bag->cons[i].adj, bag->cons[i].col), adj, col)) { + return true; + } + } + return false; +} +int main(void) { + while (EOF != scanf("%s %s bags contain", bags[len].adj, bags[len].col)) { + for ( + int i = 0; + 0 < scanf( + "%d %s %s bag%*[s,.]", + &bags[len].cons[i].cnt, + bags[len].cons[i].adj, bags[len].cons[i].col + ); + ++i + ); + scanf("no other bags."); + len++; + } + qsort(bags, len, sizeof(bags[0]), compar); + int count = 0; + for (int i = 0; i < len; ++i) { + if (canContain(&bags[i], "shiny", "gold")) count++; + } + printf("%d\n", count); +} |