InsertInterval.java

/**
 * Definition for an interval.
 * public class Interval {
 *     int start;
 *     int end;
 *     Interval() { start = 0; end = 0; }
 *     Interval(int s, int e) { start = s; end = e; }
 * }
 */
class Solution {
    public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
        List<Interval> result = new LinkedList<>();
        int i=0;
        // Add all which are less than newInterval
        while(i<intervals.size() && intervals.get(i).end<newInterval.start)
        {
            result.add(intervals.get(i++));
        }
        
        // Add newInterval
        while(i<intervals.size() && intervals.get(i).start<=newInterval.end)
        {
            newInterval = new Interval(Math.min(intervals.get(i).start,newInterval.start),
                                       Math.max(intervals.get(i).end,newInterval.end));
            i++;
        }
        result.add(newInterval);
        
        // Add rest of the intervals
        while(i<intervals.size())
            result.add(intervals.get(i++));
        return result;
    }
}