pvjc25/a1/program.c

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

int main() {
    int ch;
    int line_count = 0;

    while ((ch = getchar()) != EOF) { 
        if (islower(ch)) {  
            putchar(toupper(ch)); 
        } else if (isupper(ch)) {
            putchar(tolower(ch));  
        } else if (ch == '\n') {
            putchar(ch); 
            line_count++; 
        } else if (ch == '\t') {
            putchar(ch);  
        } else if (ch >= 32 && ch <= 126) { 
            putchar(ch);
        }
    }

    printf("\nLines count: %d\n", line_count); 

    return 0;
}