從鍵盤接收字符並輸出對應大寫或小寫

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

int main()
{
    char c = 0;
    while ( (c = getchar())  != EOF)
    {
        if (c >= 'a' && c <= 'z')
        {
            printf ("%c ",c-32);    
        }
        else if (c >= 'A' && c <= 'Z')
        {
            printf ("%c ",c+32);
        }
    }
    return 0;
}