#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * This file was generated by OpenAI and was not modified apart from this comment. The prompt was:
 *  consider a text file like this:
 *  22-65,22-66
 *  91-94,63-91
 *  6-88,5-31
 *  85-86,64-86
 *  40-65,40-65
 *  25-82,24-94
 *  
 *  write c program that:
 *  - reads a text file like this line by line and count how often one of the two ranges contains the other.
 *  - accepts the filename via command line arg
 *  - outputs the result using printf with a suitable string
 *  A range r1 contains the other r2 when the r1.lower <= r2.lower and r1.upper >= r2.upper
 *  the program needs to output how often that is the case in the entire file
 */

// 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 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) ||
            (range2.lower <= range1.lower && range2.upper >= range1.upper)) {
            count++;
        }
    }

    // Close the file
    fclose(fp);

    // Print the result
    printf("The file contains %d lines where one of the two ranges contains the other\n", count);

    return 0;
}