MagneticForceBetweenTwoBalls.java

/* https://leetcode.com/problems/magnetic-force-between-two-balls/?envType=daily-question&envId=2024-06-20 */
/* 1552. Magnetic Force Between Two Balls */

class MagneticForceBetweenTwoBalls {
    public int maxDistance(int[] position, int m) {
    Arrays.sort(position);
    int l = 1;
    int r = position[position.length - 1] - position[0];
    while (l < r) {
      final int mid = r - (r - l) / 2;
      if (numBalls(position, mid) >= m) 
        l = mid;
      else 
        r = mid - 1;
    }
    return l;
  }

  private int numBalls(int[] position, int force) {
    int balls = 0;
    int prevPosition = -force;
    for (final int pos : position)
      if (pos - prevPosition >= force) {
        balls++;
        prevPosition = pos;
      }
    return balls;
    }
}