1166-design-file-system.js

const FileSystem = function() {
  this.m = new Map()
  this.m.set('', 1)
};

/** 
 * @param {string} path 
 * @param {number} value
 * @return {boolean}
 */
FileSystem.prototype.createPath = function(path, value) {
  if(this.m.has(path)) return false
  const p = path.slice(0, path.lastIndexOf('/'))
  if(!this.m.has(p)) return false
  this.m.set(path, value)
  return true
};

/** 
 * @param {string} path
 * @return {number}
 */
FileSystem.prototype.get = function(path) {
  if(!this.m.has(path)) return -1
  return this.m.get(path)
};

/** 
 * Your FileSystem object will be instantiated and called as such:
 * var obj = new FileSystem()
 * var param_1 = obj.createPath(path,value)
 * var param_2 = obj.get(path)
 */

// another

class Node {
  constructor(v) {
    this.val = v
    this.children = new Map()
  }
}
const FileSystem = function() {
  this.r = new Node(null)
};

/** 
 * @param {string} path 
 * @param {number} value
 * @return {boolean}
 */
FileSystem.prototype.createPath = function(path, value) {
  if(path == null || path === '') return
  const arr = path.split('/').filter(e => e !== '/' && e !== '')
  let cur = this.r
  for(let i = 0, len = arr.length; i < len; i++) {
    if(i !== len - 1 && !cur.children.has(arr[i])) return false
    if(i === len - 1 && cur.children.has(arr[i])) return false 
    if(i !== len - 1) cur = cur.children.get(arr[i])
  }
  cur.children.set(arr[arr.length - 1], new Node(value))
  return true
};

/** 
 * @param {string} path
 * @return {number}
 */
FileSystem.prototype.get = function(path) {
  const arr = path.split('/').filter(e => e !== '/' && e !== '')
  let cur = this.r
  for(let i = 0, len = arr.length; i < len; i++) {
    if(!cur.children.has(arr[i])) return -1
    cur = cur.children.get(arr[i])
  }
  return cur.val
};

/** 
 * Your FileSystem object will be instantiated and called as such:
 * var obj = new FileSystem()
 * var param_1 = obj.createPath(path,value)
 * var param_2 = obj.get(path)
 */