diff options
| -rw-r--r-- | 13.c | 95 |
1 files changed, 77 insertions, 18 deletions
@@ -2,6 +2,7 @@ #include <ctype.h> #include <stdio.h> #include <stdlib.h> +#include <unistd.h> struct node { @@ -90,7 +91,7 @@ node_dump(struct node * n) int -node_cmp(struct node * l, struct node * r) +node_cmp(struct node const * l, struct node const * r) { while (l && r) { int ret; @@ -136,6 +137,13 @@ node_cmp(struct node * l, struct node * r) } +int +node_cmp_q(void const * a, void const * b) +{ + return node_cmp(*(struct node const **) a, *(struct node const **) b); +} + + struct node * node_parse(char ** ppch) { @@ -185,11 +193,24 @@ node_parse(char ** ppch) int -main() +main(int argc, char ** argv) { - struct node * packets = NULL, * last = NULL, * n; + struct node * packets = NULL, * last = NULL, * n, * sep1, * sep2; + struct node ** ppackets; char buf[BUFSIZ]; - int index_sum = 0, i; + int part = 1, npackets = 0, index_sum = 0, i; + int isep1 = -1, isep2 = -1; + + while ((i = getopt(argc, argv, "p:")) != -1) { + switch (i) { + case 'p': + part = atoi(optarg); + break; + + default: + return -1; + } + } while (fgets(buf, sizeof(buf), stdin)) { char * pch; @@ -221,28 +242,66 @@ main() else { packets = last = n; } + ++npackets; } - for (n = packets, i = 1; n != NULL && n->next != NULL; n = n->next->next, ++i) { - int j; + switch (part) { + case 1: + for (n = packets, i = 1; n != NULL && n->next != NULL; n = n->next->next, ++i) { + int j; - if ((j = node_cmp(n->val_list, n->next->val_list)) < 0) { - index_sum += i; - } + if ((j = node_cmp(n->val_list, n->next->val_list)) < 0) { + index_sum += i; + } #if 0 - node_dump(n->val_list); fputc('\n', stderr); - node_dump(n->next->val_list); fputc('\n', stderr); - fprintf(stderr, "Result: %d (%s)\n", j, j < 0 ? "yes" : "no"); + node_dump(n->val_list); fputc('\n', stderr); + node_dump(n->next->val_list); fputc('\n', stderr); + fprintf(stderr, "Result: %d (%s)\n", j, j < 0 ? "yes" : "no"); #endif - if (j == 0) { - fprintf(stderr, "Got two identical packets?\n"); - node_dump(n); fputc('\n', stderr); - node_dump(n->next); fputc('\n', stderr); + if (j == 0) { + fprintf(stderr, "Got two identical packets?\n"); + node_dump(n); fputc('\n', stderr); + node_dump(n->next); fputc('\n', stderr); + } } - } - printf("Index sum: %d\n", index_sum); + printf("Index sum: %d\n", index_sum); + break; + + case 2: + if ((ppackets = malloc((npackets + 2) * sizeof(struct node *))) == NULL) { + fprintf(stderr, "Bad malloc(%ld)\n", npackets * sizeof(struct node *)); + node_free(packets); + return -1; + } + sep1 = node_create_list(node_create_int(2)); // ??? + sep2 = node_create_list(node_create_int(6)); + ppackets[0] = sep1; + ppackets[1] = sep2; + for (n = packets, i = 2; n != NULL; n = n->next, ++i) + ppackets[i] = n->val_list; + qsort(ppackets, npackets + 2, sizeof(struct node *), node_cmp_q); + for (i = 0; i < npackets + 2; ++i) { + if (ppackets[i] == sep1) + isep1 = i; + else if (ppackets[i] == sep2) + isep2 = i; + } + + printf("Separator index product: %d (%d * %d)\n", + (isep1 + 1) * (isep2 + 1), isep1, isep2); + + node_free(sep2); + node_free(sep1); + free(ppackets); + break; + + default: + fprintf(stderr, "Unexpected puzzle part %d\n", part); + node_free(packets); + return -1; + } node_free(packets); |