Leetcode57. Insert Interval

57. Insert Interval（插入区间）

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]

.
AC代码：
 vector<Interval> insert(vector<Interval>&
intervals, Interval newInterval) {
       vector<Interval> ret;
        if(intervals.empty())
        {
            ret.push_back(newInterval);
            return ret;
        }
            
        int i = 0;
        while(i < intervals.size())
        {
            //添加的区间与已知区间没有重叠区间
            if(newInterval.end < intervals[i].start)
            {
                ret.push_back(newInterval);
                while(i < intervals.size())
                {
                    ret.push_back(intervals[i]);
                    i ++;
                }
                return ret;
            }
            else if(newInterval.start > intervals[i].end)
                ret.push_back(intervals[i]);
            //有重叠区间
            else
            {
                newInterval.start = min(newInterval.start, intervals[i].start);
                newInterval.end = max(newInterval.end, intervals[i].end);
            }
            i ++;
        }
        ret.push_back(newInterval);    
 
        return ret;
    }