Recursive personal understanding

I may not explain it scientifically:

The recursion point is above the function header, which is equivalent to a queue.
Recursion points to the end of the function, which is equivalent to stack.

The process of each recurrence is to continuously enter and exit the "above.
And "the following parts" continue to rock stack.

When baseline conditions are met, it is terminated recursively.

The regression process is to keep the Middle of the stack out of the stack.

Void f (int n) {if (n <0) return; // base condition printf ("% d", n); // queue f (n-1 ); // recursive point printf ("% d", 2 * n); // stack}