adventofcode/2020/2/parse2.c
2022-12-01 21:02:00 +01:00

32 lines
593 B
C

#include <stdio.h>
#include <stdlib.h>
int main(void) {
FILE *fp;
char line[255];
int valid = 0;
fp = fopen("input", "r");
if(fp == NULL) {
perror("Error opening file.");
return(-1);
}
while(fgets(line, sizeof(line), fp) != NULL) {
int start, end;
char subject;
char password[64];
sscanf(line, "%d-%d %c: %s\n", &start, &end, &subject, password);
if(password[start - 1] == subject && password[end - 1] != subject ||
password[end - 1] == subject && password[start - 1] != subject)
valid++;
}
fclose(fp);
printf("There are %d valid passwords\n", valid);
}