[JS] BST range sum

BSTRangeSum.js

function getBSTSum(node, range) {
  let sum = 0;
  if(!node) return sum;
  
  const [min, max] = range;
  if(node.left) sum += getBSTSum(node.left, range);
  if(node.val >= min) {
    if(node.val <= max) sum += node.val;
    else return sum;
  }
  if(node.right) sum += getBSTSum(node.right, range);
  
  return sum;
}


// ----------------------------------------- Test ----------------------------------------------- //
class Node {
  constructor(val) {
    this.val = val;
    this.left = null;
    this.right = null;    
  }
}
const node2 = new Node(2);
const node3 = new Node(3);
const node4 = new Node(4);
const node5 = new Node(5);
const node6 = new Node(6);
const node7 = new Node(7);
const node8 = new Node(8);
const node9 = new Node(9);
node6.left = node4;
node6.right = node8;
node4.left = node3;
node4.right = node5;
node3.left = node2;
node8.left = node7;
node8.right = node9;
//              6
//            /   \
//           4     8
//          / \   / \
//         3   5 7   9
//        /
//       2

console.log(getBSTSum(node6, [3,10])); //42
console.log(getBSTSum(node6, [2,5])); //14
console.log(getBSTSum(node6, [8,9])); //17
console.log(getBSTSum(node6, [4,6])); //15
console.log(getBSTSum(node6, [0,1])); //0
console.log(getBSTSum(node6, [0,11])); //44