public class BinaryTreeTestProgram2 {
public static void main(String[] args) {
   BinaryTree tree1, tree2, tree3, tree4, tree5;

   tree1 = new BinaryTree("A",
            new BinaryTree("B",
                     new BinaryTree("C",
                           new BinaryTree("D"),
                           new BinaryTree("E",
                                    new BinaryTree("F",
                                             new BinaryTree("G"),
                                             new BinaryTree("I")),
                                    new BinaryTree("H"))),
                     new BinaryTree("J",
                           new BinaryTree("K",
                                    new BinaryTree(),
                                    new BinaryTree("L",
                                             new BinaryTree(),
                                             new BinaryTree("M"))),
                           new BinaryTree("N",
                                    new BinaryTree(),
                                    new BinaryTree("O")))),
            new BinaryTree("P",
                     new BinaryTree("Q"),
                     new BinaryTree("R",
                           new BinaryTree("S",
                                    new BinaryTree("T"),
                                    new BinaryTree()),
                           new BinaryTree("U"))));
   tree2 = new BinaryTree("A",
            new BinaryTree("B",
                     new BinaryTree("C",
                           new BinaryTree("D"),
                           new BinaryTree("E",
                                    new BinaryTree("F",
                                             new BinaryTree("Z"), //different letter here
                                             new BinaryTree("I")),
                                    new BinaryTree("H"))),
                     new BinaryTree("J",
                           new BinaryTree("K",
                                    new BinaryTree(),
                                    new BinaryTree("L",
                                             new BinaryTree(),
                                             new BinaryTree("M"))),
                           new BinaryTree("N",
                                    new BinaryTree(),
                                    new BinaryTree("O")))),
            new BinaryTree("P",

(1) Given an array of integers, find two numbers such that they add...