Data commit

Task/Visualize-a-tree/Java/visualize-a-tree.java

@@ -0,0 +1,79 @@
+public class VisualizeTree {
+    public static void main(String[] args) {
+        BinarySearchTree tree = new BinarySearchTree();
+
+        tree.insert(100);
+        for (int i = 0; i < 20; i++)
+            tree.insert((int) (Math.random() * 200));
+        tree.display();
+    }
+}
+
+class BinarySearchTree {
+    private Node root;
+
+    private class Node {
+        private int key;
+        private Node left, right;
+
+        Node(int k) {
+            key = k;
+        }
+    }
+
+    public boolean insert(int key) {
+        if (root == null)
+            root = new Node(key);
+        else {
+            Node n = root;
+            Node parent;
+            while (true) {
+                if (n.key == key)
+                    return false;
+
+                parent = n;
+
+                boolean goLeft = key < n.key;
+                n = goLeft ? n.left : n.right;
+
+                if (n == null) {
+                    if (goLeft) {
+                        parent.left = new Node(key);
+                    } else {
+                        parent.right = new Node(key);
+                    }
+                    break;
+                }
+            }
+        }
+        return true;
+    }
+
+    public void display() {
+        final int height = 5, width = 64;
+
+        int len = width * height * 2 + 2;
+        StringBuilder sb = new StringBuilder(len);
+        for (int i = 1; i <= len; i++)
+            sb.append(i < len - 2 && i % width == 0 ? "\n" : ' ');
+
+        displayR(sb, width / 2, 1, width / 4, width, root, " ");
+        System.out.println(sb);
+    }
+
+    private void displayR(StringBuilder sb, int c, int r, int d, int w, Node n,
+            String edge) {
+        if (n != null) {
+            displayR(sb, c - d, r + 2, d / 2, w, n.left, " /");
+
+            String s = String.valueOf(n.key);
+            int idx1 = r * w + c - (s.length() + 1) / 2;
+            int idx2 = idx1 + s.length();
+            int idx3 = idx1 - w;
+            if (idx2 < sb.length())
+                sb.replace(idx1, idx2, s).replace(idx3, idx3 + 2, edge);
+
+            displayR(sb, c + d, r + 2, d / 2, w, n.right, "\\ ");
+        }
+    }
+}