From e0c2037ee5cede636e907e8af462371ee0e775db Mon Sep 17 00:00:00 2001 From: Adam Spragg Date: Sun, 4 Dec 2022 16:47:21 +0000 Subject: Advent of code 2022 problems 1-4 --- 4a.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 4a.c (limited to '4a.c') diff --git a/4a.c b/4a.c new file mode 100644 index 0000000..76d5e0c --- /dev/null +++ b/4a.c @@ -0,0 +1,53 @@ + +#include +#include + + +char * +getsect(int * dest, char * pch, char expect) +{ + char * end; + + if (!pch) + return NULL; + *dest = strtol(pch, &end, 10); + if (*dest == 0 && end == pch) + return NULL; + if (*end != expect) + return NULL; + if (expect) + ++end; + return end; +} + + +int +main() +{ + char buf[BUFSIZ]; + int overlaps = 0; + + while (fgets(buf, sizeof(buf), stdin)) { + int n[4]; + char * pbuf; + + pbuf = getsect(&n[0], buf, '-'); + pbuf = getsect(&n[1], pbuf, ','); + pbuf = getsect(&n[2], pbuf, '-'); + pbuf = getsect(&n[3], pbuf, '\n'); + if (!pbuf) { + fprintf(stderr, "Unexpected line: %s\n", buf); + return -1; + } + if ((n[2] >= n[0] && n[3] <= n[1]) + || (n[0] >= n[2] && n[1] <= n[3])) + { + ++overlaps; + } + } + + printf("Overlaps: %d\n", overlaps); + + return 0; +} + -- cgit v1.2.1