treenode.js

treenode.js

class TreeNode {
        constructor(val) {
            this.val = val;
            this.left = null;
            this.right = null;
        }
    }
    
    let a = new TreeNode('a');
    let b = new TreeNode('b');
    let c = new TreeNode('c');
    let d = new TreeNode('d');
    let e = new TreeNode('e');
    let f = new TreeNode('f');
    
    a.left = b;
    a.right = c;
    b.left = d;
    b.right = e;
    c.right = f;