class Solution {public:    int maxDistToClosest(vector
     
      & seats) {        int first = 0, last = seats.size() - 1;        while (seats[first] == 0)   first++;        while (seats[last] == 0)    last--;        int md = 0, d = 0;        for (int i = first + 1; i <= last; i++) {            if (seats[i] == 0)                d++;            else {                md = max(md, d);                d = 0;            }        }        return max(max(first, (int)seats.size() - last - 1), (md + 1) / 2);    }};