AdventOfCode2022/04/day4.c

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2022-12-08 01:46:35 +01:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Structure to represent a range in the file
struct range {
int lower;
int upper;
};
// Function to parse a line from the file and return the two ranges in the line
void parse_line(const char *line, struct range *range1, struct range *range2) {
// Parse the two ranges in the line
sscanf(line, "%d-%d,%d-%d", &range1->lower, &range1->upper, &range2->lower, &range2->upper);
}
int main(int argc, char *argv[]) {
// Check if a filename was provided
if (argc < 2) {
fprintf(stderr, "Error: No filename provided\n");
return 1;
}
// Open the file for reading
FILE *fp = fopen(argv[1], "r");
if (fp == NULL) {
fprintf(stderr, "Error: Unable to open file for reading\n");
return 1;
}
// Read the file line by line
char line[256];
int contain_count = 0;
int overlap_count = 0;
while (fgets(line, sizeof(line), fp) != NULL) {
// Parse the two ranges in the line
struct range range1, range2;
parse_line(line, &range1, &range2);
// Check if one range contains the other
if (range1.lower <= range2.lower && range1.upper >= range2.upper) {
contain_count++;
}
else if (range2.lower <= range1.lower && range2.upper >= range1.upper) {
contain_count++;
}
// Check if one range overlaps with the other
else if (range1.lower == range2.lower ||
range1.upper == range2.upper ||
(range1.lower > range2.lower && range1.lower <= range2.upper) ||
(range1.upper < range2.upper && range1.upper >= range2.lower)) { // had to fix range1.upper < range2.upper comparison
overlap_count++;
}
}
// Close the file
fclose(fp);
// Print the results
printf("The file contains %d lines where one of the two ranges contains each other\n", contain_count);
printf("The file contains %d lines where the two ranges overlap each other\n", overlap_count);
return 0;
}