JavaScript Clean DFS Solution
javascript\nvar isValidSerialization = function(preorder) {\n    const arr = preorder.split(\',\');\n    let i = 0;\n    \n    function callDFS() {\n        if(
```javascript\nvar isValidSerialization = function(preorder) {\n    const arr = preorder.split(\',\');\n    let i = 0;\n    \n    function callDFS() {\n        if(i >= arr.length) return false;        \n        if(arr[i++] === \'#\') return true;\n        return callDFS() && callDFS();\n    }\n    return callDFS() && i == arr.length;\n};\n```
['Depth-First Search', 'Recursion', 'JavaScript']