CSC403: Tree code: Local variables don't matter [18/29]

    public int size () {
        return size (root);
    }
    private static int size (Node x) {
        if (x == null) return 0;
        int szl = size (x.left);
        int szr = size (x.right);
        return szl + szr + 1;
    }

Local variables don't matter.

Here is a trace of an execution.

This is static single assignment (SSA) form: each variable is assigned on exactly one line of code.

Most compilers translate your code into SSA as part of the compilation process.

In SSA, the right-hand-side of the assignment may be restricted to be either a single function call or a single operator. In this case, the last line would be translated to:

        int tmp1 = szl + szr;
        int tmp2 = tmp1 + 1;
        return tmp2;

Note: You don't need to remember SSA for exams. It's informational.