Write a function, breadthFirstValues, that takes in the root of a binary tree. The function should return an array containing all values of the tree in breadth-first order.
test_00:
const a = new Node('a');
const b = new Node('b');
const c = new Node('c');
const d = new Node('d');
const e = new Node('e');
const f = new Node('f');
a.left = b;
a.right = c;
b.left = d;
b.right = e;
c.right = f;
// a
// / \
// b c
// / \ \
// d e f
breadthFirstValues(a);
// -> ['a', 'b', 'c', 'd', 'e', 'f']test_01:
const a = new Node('a');
const b = new Node('b');
const c = new Node('c');
const d = new Node('d');
const e = new Node('e');
const f = new Node('f');
const g = new Node('g');
const h = new Node('h');
a.left = b;
a.right = c;
b.left = d;
b.right = e;
c.right = f;
e.left = g;
f.right = h;
// a
// / \
// b c
// / \ \
// d e f
// / \
// g h
breadthFirstValues(a);
// -> ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']test_02:
const a = new Node('a');
// a
breadthFirstValues(a);
// -> ['a']test_03:
const a = new Node('a');
const b = new Node('b');
const c = new Node('c');
const d = new Node('d');
const e = new Node('e');
const x = new Node('x');
a.right = b;
b.left = c;
c.left = x;
c.right = d;
d.right = e;
// a
// \
// b
// /
// c
// / \
// x d
// \
// e
breadthFirstValues(a);
// -> ['a', 'b', 'c', 'x', 'd', 'e']test_04:
howHigh(null);
// -> []