leetcode-com-explore-challenge-card-july-leetcoding-challenge-544-week-1-july-1st-july-7th-3379.cpp

class Solution {
public:    
    vector<int> prisonAfterNDays(vector<int>& cells, int N) {
        int n = cells.size(), cycle = 0;
        vector<int> cur(n, 0), direct;
        while(N-- > 0) {
            for(int i = 1; i < n - 1; ++i) cur[i] = cells[i - 1] == cells[i + 1];
            if(direct.empty()) direct = cur;
            else if(direct == cur) N %= cycle;

            ++cycle;
            cells = cur;
        }
        return cur;
    }
};