advent2021

Advent of Code 2021 Solutions
git clone git://bsandro.tech/advent2021
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puzzle1.c (616B)

      1 #include <stdio.h>
      2 #include <stdlib.h>
      3 #include <errno.h>
      4 #include <string.h>
      5 #include <strings.h>
      6 
      7 #define MAX_LEN 8
      8 
      9 int puzzle1(const char *filename) {
     10 	FILE *infile = fopen(filename, "r");
     11 	if (infile == NULL) {
     12 		fprintf(stderr, "fopen() error: %s\n", strerror(errno));
     13 		return -1;
     14 	}
     15 
     16 	char buf[MAX_LEN] = {0};
     17 	int prev_depth = -1;
     18 	int counter = 0;
     19 
     20 	while (fgets(buf, MAX_LEN, infile) != NULL) {
     21 		int depth = atoi(buf);
     22 		if (prev_depth > -1 && depth > prev_depth) {
     23 			++counter;
     24 		}
     25 		prev_depth = depth;
     26 		bzero(buf, MAX_LEN);
     27 	}
     28 
     29 	// mutiny! ignoring feof/ferror.
     30 
     31 	fclose(infile);
     32 	return counter;
     33 }