[LeetCode] 57. Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

You may assume that the intervals were initially sorted according to their start times.

Example 1:
Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].

Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].

This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].

/**
 * 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; }
 * }
 */
public class Solution {
    public List insert(List intervals, Interval newInterval) {
        
        List ret = new ArrayList();
        
        int len = intervals.size();
        
        for(int i = 0; i < len; ++i){
            Interval c = intervals.get(i);
            if(c.start > newInterval.end){
                ret.add(newInterval);
                ret.addAll(intervals.subList(i, len));
                return ret;
            }else if(c.end < newInterval.start){
                ret.add(c);
            }else{
                newInterval.start = Math.min(newInterval.start, c.start);
                newInterval.end = Math.max(newInterval.end, c.end);
            }
        }
        
        ret.add(newInterval);
        return ret;
    }
}