Codility: StoneWall Solution

Implementation

1function Stack() {
2  stack = []
3
4  this.push = function (el) {
5    stack.push(el)
6  }
7
8  this.pop = function () {
9    return stack.pop()
10  }
11
12  return {
13    ...this,
14    get size() {
15      return stack.length
16    },
17    get head() {
18      return stack[this.size - 1]
19    },
20  }
21}
22
23function solution(H) {
24  let stack = new Stack()
25  let count = 0
26  H.forEach(h => {
27    while (stack.size && stack.head > h) {
28      stack.pop()
29    }
30    if (stack.size && stack.head === h) {
31      return
32    }
33    stack.push(h)
34    count++
35  })
36  return count
37}

References

https://codility.com/media/train/solution-stone-wall.pdf