LeetCode: Simplify Path Solution

Approach

Split the task by slash /

Sanitize

• remove . because it is the current folter
• remove blank because it is redundant

Use stack, if part is .. the pop the part, else push the part

Implementation

1function Stack() {
2  const stack = []
3
4  this.push = function (el) {
5    stack.push(el)
6  }
7
8  this.pop = function () {
9    return stack.pop()
10  }
11
12  this.peek = function () {
13    return stack[stack.length - 1]
14  }
15
16  this.isEmpty = function () {
17    return stack.length === 0
18  }
19}
20
21/**
22 * @param {string} path
23 * @return {string}
24 */
25var simplifyPath = function (path) {
26  path = path
27    .split("/")
28    .filter(Boolean)
29    .filter(part => part !== ".")
30
31  const stack = new Stack()
32  for (const part of path) {
33    if (part === "..") {
34      stack.pop()
35    } else {
36      stack.push(part)
37    }
38  }
39  const res = []
40  while (!stack.isEmpty()) {
41    res.push(stack.pop())
42  }
43  res.reverse()
44  return "/" + res.join("/")
45}