Package g0901_1000.s0957_prison_cells_after_n_days

Class Solution

  • public class Solution
extends Object
    957 - Prison Cells After N Days.

    Medium

    There are 8 prison cells in a row and each cell is either occupied or vacant.

    Each day, whether the cell is occupied or vacant changes according to the following rules:

    • If a cell has two adjacent neighbors that are both occupied or both vacant, then the cell becomes occupied.
    • Otherwise, it becomes vacant.

    Note that because the prison is a row, the first and the last cells in the row can’t have two adjacent neighbors.

    You are given an integer array cells where cells[i] == 1 if the ith cell is occupied and cells[i] == 0 if the ith cell is vacant, and you are given an integer n.

    Return the state of the prison after n days (i.e., n such changes described above).

    Example 1:

    Input: cells = [0,1,0,1,1,0,0,1], n = 7

    Output: [0,0,1,1,0,0,0,0]

    Explanation: The following table summarizes the state of the prison on each day:

    Day 0: [0, 1, 0, 1, 1, 0, 0, 1]

    Day 1: [0, 1, 1, 0, 0, 0, 0, 0]

    Day 2: [0, 0, 0, 0, 1, 1, 1, 0]

    Day 3: [0, 1, 1, 0, 0, 1, 0, 0]

    Day 4: [0, 0, 0, 0, 0, 1, 0, 0]

    Day 5: [0, 1, 1, 1, 0, 1, 0, 0]

    Day 6: [0, 0, 1, 0, 1, 1, 0, 0]

    Day 7: [0, 0, 1, 1, 0, 0, 0, 0]

    Example 2:

    Input: cells = [1,0,0,1,0,0,1,0], n = 1000000000

    Output: [0,0,1,1,1,1,1,0]

    Constraints:

    • cells.length == 8
    • cells[i] is either 0 or 1.
    • 1 <= n <= 109

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • prisonAfterNDays

        public int[] prisonAfterNDays​(int[] cells,
                              int n)