Uber interview question

overlaping.java

public class Interview {

  class Interval {
    int start;
    int end;
    
    public Interval(int start, int end) {
      this.start = start;
      this.end = end;
    }
  }
  
  
  public static void main(String[] args) {
    Interval i1 = new Interval(1,2);
    Interval i2 = new Interval(2,4);
    Interval i3 = new Interval(3,8);
    Interval i4 = new Interval(4,12);
    
    List<Interval> intervals = new ArrayList<>();
    intervals.add(i1);
    intervals.add(i2);
    intervals.add(i3);
    intervals.add(i4);
    intervals.add(i5);
    
    merge(intervals);
    
  }
  
  
  public static List<Interval> merge(List<Interval> intervals) {
        // Sort the intervals
        Collections.sort(intervals,new IntervalComaparator());  

        List<Interval> result = new List<>();
        Stack<Interval> stack = new Stack<>();
        stack.push(intervals.get(0));
        
        for (int i = 1; i < intervals.size(); i++) {
            Interval currentTime = intervals.get(i);
            Interval onStack = stack.pop();

            if (isInInterval(onStack, currentTime)) {
                result.add(new Interval(onStack.start, Math.max(onStack.end, currentTime.end)));
                stack.push(intervals.get(i));
                i++;
            } else {
                stack.push(currentTime);
                result.add(onStack);
            }
        }

        return result;
  }


  public static boolean isInInterval(Interval i, Interval j) {
      if (i.end >= j.start) return true;
      return false;
  }

  class IntervalComaparator implements Comparator<Interval>{  
      public int compare(Interval i1,Interval i2){  
          if (i1.start == s2.start) return 0;
          if (i1.start > i2.start) return 1;
          return -1;
      }  
  }   


}