The challenge

You are given an array representing a row of seats where seats[i] = 1 represents a person sitting in the i<sup>th</sup> seat, and seats[i] = 0 represents that the i<sup>th</sup> seat is empty (0-indexed).

There is at least one empty seat, and at least one person sitting.

Alex wants to sit in the seat such that the distance between him and the closest person to him is maximized. 

Return that maximum distance to the closest person.

Example 1:

Example 2:

Example 3:

Constraints:

  • 2 <= seats.length <= 2 * 10<sup>4</sup>
  • seats[i] is `` or 1.
  • At least one seat is empty.
  • At least one seat is occupied.

The solution in Java code

public class MaximizeDistancetoClosestPerson {
    public int maxDistToClosest(int[] seats) {
        int maxSpace = -1;
        int alex = 0;
        for(int i=0;i<seats.length;i++){
            int start = i;
            while(i+1<seats.length && seats[i]+seats[i+1]==0){
                i++;
            }
            if(maxSpace<=i-start){
                if(i==seats.length-1 || start==0) alex = i-start+1;
                else alex = (i-start)/2 +1;
                maxSpace = Math.max(maxSpace,alex);
            }
        }
        return maxSpace;
    }
}

Test cases to validate our Java solution

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class MaximizeDistancetoClosestPersonTest {

    @Test
    void maxDistToClosest_case1() {
        int actual = new MaximizeDistancetoClosestPerson().maxDistToClosest(new int[]{1,0,0,0,1,0,1});
        assertEquals(2, actual);
    }

    @Test
    void maxDistToClosest_case2() {
        int actual = new MaximizeDistancetoClosestPerson().maxDistToClosest(new int[]{1,0,0,0});
        assertEquals(3, actual);
    }

    @Test
    void maxDistToClosest_case3() {
        int actual = new MaximizeDistancetoClosestPerson().maxDistToClosest(new int[]{0,1});
        assertEquals(1, actual);
    }
}