diff --git a/src/Traversal.java b/src/Traversal.java deleted file mode 100644 index 8da0f79..0000000 --- a/src/Traversal.java +++ /dev/null @@ -1,5 +0,0 @@ -public class Traversal { - public static void main(String[] args) { - - } -} diff --git a/src/TreeNode.java b/src/TreeNode.java index acd9639..23beaec 100644 --- a/src/TreeNode.java +++ b/src/TreeNode.java @@ -1,4 +1,12 @@ -public class TreeNode { +public class TreeNode { + public T value; + public TreeNode left; + public TreeNode right; + + public TreeNode(T value, TreeNode left, TreeNode right){ + this.value = value; + this.left = left; + this.right = right; + } - } \ No newline at end of file diff --git a/src/toMap.java b/src/toMap.java new file mode 100644 index 0000000..c57441c --- /dev/null +++ b/src/toMap.java @@ -0,0 +1,136 @@ + +import java.util.HashMap; +import java.util.Map; +import java.util.Stack; + +public class toMap { + public static void main(String[] args) { + TreeNode root = new TreeNode<>(2, null, null); + root.left = new TreeNode<>(1, null, null); + root.left.left = new TreeNode<>(7, null, null); + root.left.right = new TreeNode<>(4, null, null); + + root.right = new TreeNode<>(3, null, null); + root.right.left = new TreeNode<>(5, null, null); + root.right.right = new TreeNode<>(6, null, null); + root.right.right = new TreeNode<>(9, null, null); + root.right.right.right = new TreeNode<>(8, null, null); + + TreeNode stringRoot = new TreeNode<>("hello",null,null); + stringRoot.left = new TreeNode<>("hello", null, null); + stringRoot.left.left = new TreeNode<>("hello", null, null); + stringRoot.left.right = new TreeNode<>("hello", null, null); + + stringRoot.right = new TreeNode<>("am", null, null); + stringRoot.right.left = new TreeNode<>("am", null, null); + stringRoot.right.right = new TreeNode<>("am", null, null); + stringRoot.right.right.right = new TreeNode<>("good", null, null); + + TreeNode megaRoot = new TreeNode(1, null, null); + + TreeNode current = megaRoot; + + for(int i = 2; i <= Integer.MAX_VALUE; i++){ + current.right = new TreeNode(i, null, null); + current = current.right; + } + // System.out.println("Preorder recursive"); + // preorder(root); + // System.out.println("Preorder iterative"); + // preOrderIter(root); + preOrderIter(megaRoot); + + // System.out.println(toMap(stringRoot)); + } + + public static void levelOrder(TreeNode node){ + Queue> queue = new LinkedList<>(); + + queue.add(node); + + while(!queue.isEmpty()){ + TreeNode current = queue.poll(); + + if(current == null){ + continue; + } + + System.out.print(current.value + " "); + queue.add(current.left); + queue.add(current.right); + } + } + + public static void preorder(TreeNode node){ + if(node == null) return; + System.out.println(node.value); + preorder(node.left); + preorder(node.right); + } + + public static void preOrderIter(TreeNode node){ + Stack> stack = new Stack<>(); + stack.push(node); + + while(!stack.isEmpty()){ + TreeNode current = stack.pop(); + + if(current == null){ + continue; + } + + System.out.println(current.value); + stack.push(current.right); + stack.push(current.left); + + } + } + + public static Map toMap(TreeNode node){ + Map counts = new HashMap<>(); + toMap(node, counts); + return counts; + } + + private static void toMap(TreeNode node, Map counts){ + if(node == null){ + return; + } + + // fill up those counts + counts.put(node.value, counts.getOrDefault(node.value, 0) + 1); + + toMap(node.left, counts); + toMap(node.right, counts); + } + + public static int countNodes(TreeNode node){ + return node == null ? 0 : 1 + countNodes(node.left) + countNodes(node.right); + } + + public static void printGreater(TreeNode node, int threshold){ + if(node == null) return; + if(node.value > threshold){ + System.out.println(node.value); + + } + printGreater(node.left,threshold); + printGreater(node.right,threshold); + } + + public static void inorder(TreeNode node){ + if(node == null) return; + inorder(node.left); + System.out.print(node.value + " "); + inorder(node.right); + } + + public static void postorder(TreeNode node){ + if(node == null) return; + postorder(node.left); + postorder(node.right); + System.out.print(node.value + " "); + } + + +} \ No newline at end of file