c Value output using language pointer function.

First of all, I can't.

This is because the function set_to_five() does not run in the main function.

So if you think about the alternative,

void set_to_five(int* a){
    *a=15;
}

int main(){
    int foo = 0;
    int bar = 0;
    int glorp = 0;

    set_to_five(&foo);

    printf("%d", foo+7*bar+2*glorp);
    return  0;
}

But I made a function with a pointer.

(bar and glorp variables are not used.)

We changed the value of foo to 15 by executing the set_to_five function in the middle.