pvjc24/cv1/program.c

#include <stdio.h>

int main() {
    int c = 0; 
    int lines_count = 0;

    while ((c = getchar()) != EOF) {
        if (c == '\n') {

            lines_count++;
        } else if (c >= 'a' && c <= 'z') {

            c = c - 'a' + 'A';
        } else if (c >= 'A' && c <= 'Z') {

            c = c - 'A' + 'a';
        }
        
        putchar(c);
    }

    printf("Lines Count: %d\n", lines_count);

    return 0;
}