How to find maximum in Java binary tree?

Question

Java

my code:

public int max(Tree node) {
        int cur = (int) node.val();
        return maxInter(node, cur);
    }

    public int maxInter(Tree node, int maxValue) {
        if (node == null) {
            return maxValue;
        } else {
            int currentElement = (int) node.val;
            int tmpMaxValue = Math.max(currentElement, maxValue);
            maxInter(node.left, tmpMaxValue);
            maxInter(node.right, tmpMaxValue);
            System.out.println(tmpMaxValue); // просмотр макс значений
            return tmpMaxValue;
        }
    }

where is the mistake?

Answer 1

The fact that you assign an int to a parameter inside the function is not visible outside the function (the variable is passed by value, not by reference). Therefore, the result of recursive calls should be taken from the returned value, rather than hoping that the function itself will update tmpMaxValue.

Answer 2

That the results of recursive calls are not used.