[해커랭크] Tree: Preorder Traversal [JAVA]

문제링크 : www.hackerrank.com/challenges/tree-preorder-traversal/problem

Tree: Preorder Traversal | HackerRank

 

public static void preOrder(Node root) {
        if(root==null) return;
        System.out.print(root.data + " ");
        preOrder(root.left);
        preOrder(root.right);
    }