Nested Functions

Listing 5: countHelper() written as a nested function.

class Tree
{
    Tree left;
    Tree right;
}
void doCount(Tree t)
{
    int count = 0;
    void countHelper(Tree t)
    {
    while (t)
    {   count++;
        countHelper(t.right);
        t = t.left;
    }
    }
    countHelper(t);
    printf("number of nodes in tree = %d\n", count);
}