588. Design In-Memory File System

https://leetcode.com/problems/design-in-memory-file-system/

Python

Javascript

 var FileSystem = function() {
  this.root = { childs: {} };
};

/**
 * @param {string} path
 * @return {string[]}
 */
FileSystem.prototype.ls = function(path) {
  const node = this.traverse(path);

  const ary = [];
  if (node.isFile) {
    ary.push(node.name);
  } else {
    for (const key in node.childs) {
      const child = node.childs[key];
      ary.push(child.name)
    }
  }
  ary.sort();
  return ary;
};

/**
 * @param {string} path
 * @return {void}
 */
FileSystem.prototype.mkdir = function(path) {
  this.traverse(path);
};

/**
 * @param {string} filePath
 * @param {string} content
 * @return {void}
 */
FileSystem.prototype.addContentToFile = function(filePath, content) {
    const node = this.traverse(filePath)
  node.isFile = true;
  node.content = (node.content || '') + content;
};

/**
 * @param {string} filePath
 * @return {string}
 */
FileSystem.prototype.readContentFromFile = function(filePath) {
  const node = this.traverse(filePath);
  return node.content;

};

FileSystem.prototype.traverse = function(filePath) {
  const paths = filePath.split('/')
  let node = this.root;
  for (let i = 1; i < paths.length; i++) {
    const path = paths[i];
    if (path) {
      if (!node.childs[path]) {
        node.childs[path] = { childs: {}, name: path };
      }
      node = node.childs[path];
    }
  }
  return node;
}