// Program to test solutions to problem #8 on the cse143 final, spring 2010.
// Fill in your solution to removeLeftLeaves, then compile and run the program

import java.util.*;

class IntTree {
    public void removeLeftLeaves() {
        // fill in your solution here and include any private methods below
    }

    private IntTreeNode overallRoot;

    // this is the sample solution
    public void removeLeftLeaves2() {
        removeLeftLeaves(overallRoot, false);
    }

    private IntTreeNode removeLeftLeaves(IntTreeNode root, boolean left) {
        if (root != null) {
            root.left = removeLeftLeaves(root.left, true);
            removeLeftLeaves(root.right, false);
            if (left && root.left == null && root.right == null)
                root = null;
        }
        return root;
    }

    // post: constructs an empty tree
    public IntTree() {
        overallRoot = null;
    }

    // pre : the tree satisfies the binary search tree property
    // post: value is added so as to preserve the binary search tree property
    public void add(int value) {
        overallRoot = add(overallRoot, value);
    }

    // pre : the tree with given root satisfies the binary search tree property
    // post: value is added so as to preserve the binary search tree property
    private IntTreeNode add(IntTreeNode root, int value) {
        if (root == null)
            root = new IntTreeNode(value);
        else if (value <= root.data)
            root.left = add(root.left, value);
        else
            root.right = add(root.right, value);
        return root;
    }

    // post: prints the data fields of the tree, one per line, following
    //       an inorder traversal and using indentation to indicate node depth;
    //       prints right to left so that it looks correct when the output is
    //       rotated.
    public void printStructure() {
        printStructure(overallRoot, 0);
    }

    // post: prints in preorder the data fields of the given tree indenting
    //       each line to the given level
    private void printStructure(IntTreeNode root, int level) {
        if (root != null) {
            printStructure(root.right, level + 1);
            for (int i = 0; i < level; i++)
                System.out.print("    ");
            System.out.println(root.data);
            printStructure(root.left, level + 1);
        }
    }

    // returns true if this tree equals other tree
    public boolean equals(IntTree other) {
        return equals(overallRoot, other.overallRoot);
    }

    private boolean equals(IntTreeNode root1, IntTreeNode root2) {
        if (root1 == null || root2 == null)
            return root1 == null && root2 == null;
        else
            return root1.data == root2.data
                && equals(root1.left, root2.left)
                && equals(root1.right, root2.right);
    }
}

public class FinalTest8 {
    public static void main(String[] args) {
        for (int i = 0; i < 30; i++)
            test(i);
    }

    public static void test(int n) {
        IntTree t1 = new IntTree();
        IntTree t2 = new IntTree();
        Random r = new Random();
        for (int i = 0; i < n; i++) {
            int next = r.nextInt(100);
            t1.add(next);
            t2.add(next);
        }
        System.out.println("Testing this tree:");
        t1.printStructure();
        System.out.println("Expected result:");
        t1.removeLeftLeaves2();
        t1.printStructure();
        boolean fail = false;
        try {
            t2.removeLeftLeaves();
        } catch (RuntimeException e) {
            System.out.println("    threw " + e);
            fail = true;
        }
        if (!fail && (!t1.equals(t2))) {
            System.out.println("actual result:");
            t2.printStructure();
            fail = true;
        }
        if (fail)
            System.out.println("failed");
        else
            System.out.println("passed");
        System.out.println("---------------------------------------------");
    }
}

class IntTreeNode {
    public int data;       // data stored at this IntTreeNode
    public IntTreeNode left;  // reference to left subtree
    public IntTreeNode right; // reference to right subtree
        
    // post: constructs a leaf node with given data
    public IntTreeNode(int data) {
        this(data, null, null);
    }
                
    // post: constructs a IntTreeNode with the given data and links
    public IntTreeNode(int data, IntTreeNode left, IntTreeNode right) {
        this.data = data;
        this.left = left;
        this.right = right;
    }
}