pvjc24/cv1/program.c

#include <stdio.h>
#include <ctype.h>

int main() {
    char input_char;
    int line_count = 0;

    while (1) {
        int read_result = scanf("%c", &input_char);

        if (read_result == EOF) {
            break;
        }

        if (islower(input_char)) {
            printf("%c", toupper(input_char));
        } else if (isupper(input_char)) {
            printf("%c", tolower(input_char));
        } else if (input_char == '\n') {
            line_count++;
            printf("%c", input_char);
        } else if (isprint(input_char)) {
            // Print visible characters as they are
            printf("%c", input_char);
        }
    }

    printf("\nNumber of lines read: %d\n", line_count);

    return 0;
}