Recursion

Consider the following function written in the C programming language.

void foo(char *a){
    if ( *a && *a != ' '){
        foo(a+1);
        putchar(*a);
    }
}

The output of the above function on input "ABCD EFGH" is

Consider the following C function.

int fun(int n){
    int x=1, k;
    if (n==1) return x;
    for (k=1; k<n; ++k)
        x = x + fun(k) * fun(n-k);
    return x;
}

The return value of fun(5) is _____.

Consider the following recursive C function.

void get (int n)
{
    if (n<1) return;
    get(n-1);
    get(n-3);
    printf("%d", n);
}

If get(6) function is being called in main() then how many times will the get() function be invoked before returning to the main()?