// input: object -- node in a tree
// output: number -- largest sum for a layer of the tree
// alg: look at the given node and set the return value to its value. then sum its children, if the children sum to more than the value of the node, set
// the return value to their sum. recursively call on the children of the children in the current level summing them and determining if their sum is higher than the
// return value, updating it as necessary.

const findLargestLevel = function(node) {
  let highestLayer = node.value;
  if (node.children) {
    let layerTotal = 0;
    node.children.forEach(child => {
      layerTotal += child.value;
    });
    highestLayer = layerTotal > highestLayer ? layerTotal : highestLayer;
    sumChildren(node.children);
  }

  function sumChildren(arr) {
    let layerTotal = 0;
    arr.forEach(node => {
      if (node.value) {
        layerTotal += node.value;
      }
    });
    highestLayer = layerTotal > highestLayer ? layerTotal : highestLayer;
    let nextArr = arr.map(node => {
      if (node.children) {
        return node.children;
      }
    });
    if (nextArr.length) {
      sumChildren(nextArr);
    }
  }
  return highestLayer;
};