1
/**
2
 * @param {number[]} cells
3
 * @param {number} n
4
 * @return {number[]}
5
 */
6

7
var prisonAfterNDays = function (cells, n) {
8
  const set = new Set();
9
  let cycleDuration = 0;
10

11
  while (n--) {
12
    const nextCells = getNextCells(cells);
13

14
    // 1. Get cycle length
15
    if (!set.has(String(nextCells))) {
16
      set.add(String(nextCells));
17
      cycleDuration++;
18
      cells = nextCells;
19
    } else {
20
      // 2. Use cycle length to iterate once more to get to correct order
21
      let remainderToMove = n % cycleDuration;
22
      while (remainderToMove >= 0) {
23
        remainderToMove--;
24
        cells = getNextCells(cells);
25
      }
26
      break;
27
    }
28
  }
29

30
  return cells;
31
};
32

33
function getNextCells(cells) {
34
  let temp = [...cells];
35
  for (let i = 0; i < 8; i++) {
36
    if (i > 0 && i < 7 && cells[i - 1] === cells[i + 1]) {
37
      temp[i] = 1;
38
    } else {
39
      temp[i] = 0;
40
    }
41
  }
42

43
  return temp;
44
}
45

46
// 0
47
// 1
48
// 2
49
// n
50

51
// 1 000 000 % n