1552 - Magnetic Force Between Two Balls

 JAVA

• class Solution {
      public int maxDistance(int[] position, int m) {
          Arrays.sort(position);
          int left = 1, right = position[position.length - 1];
          while (left < right) {
              int mid = (left + right + 1) >>> 1;
              if (check(position, mid, m)) {
                  left = mid;
              } else {
                  right = mid - 1;
              }
          }
          return left;
      }
  
      private boolean check(int[] position, int f, int m) {
          int prev = position[0];
          int cnt = 1;
          for (int i = 1; i < position.length; ++i) {
              int curr = position[i];
              if (curr - prev >= f) {
                  prev = curr;
                  ++cnt;
              }
          }
          return cnt >= m;
      }
  }

C++

• class Solution {
  public:
      int maxDistance(vector<int>& position, int m) {
          sort(position.begin(), position.end());
          int left = 1, right = position[position.size() - 1];
          while (left < right) {
              int mid = (left + right + 1) >> 1;
              if (check(position, mid, m))
                  left = mid;
              else
                  right = mid - 1;
          }
          return left;
      }
  
      bool check(vector<int>& position, int f, int m) {
          int prev = position[0];
          int cnt = 1;
          for (int i = 1; i < position.size(); ++i) {
              int curr = position[i];
              if (curr - prev >= f) {
                  prev = curr;
                  ++cnt;
              }
          }
          return cnt >= m;
      }
  };