1
var smallestFromLeaf = function (root) {
2
  if (root === null) return "";
3

4
  let queue = [[root, "" + giveCharacter(root.val)]];
5
  let leafLevelFound = false;
6
  let possibleSmallString = [];
7

8
  while (queue.length > 0) {
9
    let currentLevelLength = queue.length;
10

11
    for (let i = 0; i < currentLevelLength; i++) {
12
      let [currentNode, currentPath] = queue.shift();
13

14
      if (currentNode.left === null && currentNode.right === null) {
15
        // as one of the test case is failing with this approacch - saying legth/depth of the path doesnt matter
16
        // even TOTAL (ASCII)SUM of letters also not matter - it should be dictionary first path
17
        // hence, no need of this logic and have to continue until all path discovered
18
        // So, instead removing - just never doing TRUE - hence it will continue exploring and putting all paths
19
        leafLevelFound = false;
20
        possibleSmallString.push(currentPath); //.split("").reverse().join("")
21
      }
22

23
      if (!leafLevelFound) {
24
        if (currentNode.left !== null)
25
          queue.push([
26
            currentNode.left,
27
            giveCharacter(currentNode.left.val) + currentPath,
28
          ]);
29
        if (currentNode.right !== null)
30
          queue.push([
31
            currentNode.right,
32
            giveCharacter(currentNode.right.val) + currentPath,
33
          ]);
34
      }
35
    }
36

37
    if (leafLevelFound) break;
38
  }
39

40
  // console.log(possibleSmallString);
41
  possibleSmallString.sort();
42
  // console.log(possibleSmallString);
43
  return possibleSmallString[0];
44
};
45

46
function giveCharacter(num) {
47
  return String.fromCharCode(num + 97);
48
}