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

80 lines
2.1 KiB
Java

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, "\\ ");
}
}
}