Codility: Fish Solution

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(A, B) {
24  const stack = new Stack()
25  for (let i = 0; i < A.length; i++) {
26    let curr = { A: A[i], B: B[i] }
27    if (!stack.head) {
28      stack.push(curr)
29      continue
30    }
31
32    if (stack.head.B === 1 && curr.B === 0) {
33      let head
34      while (1) {
35        head = stack.pop()
36        const winner = head.A > curr.A ? head : curr
37        curr = winner
38        if (!(stack.head && stack.head.B === 1 && curr.B === 0)) {
39          stack.push(winner)
40          break
41        }
42      }
43    } else {
44      stack.push(curr)
45    }
46  }
47  return stack.size
48}