57. Insert Interval(插入区间)

原题链接：https://leetcode.com/problems/insert-interval/

思路是在区间重复时不断更新newInterval（新的左边界，新的右边界），

直到下一个的start边界大于newInterval的end边界。

AC 6ms Java 99.6%:

/**
 * 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> ans=new ArrayList();
        int i=0;
        while(i<intervals.size()&&intervals.get(i).end<newInterval.start){
            ans.add(intervals.get(i++));
        }
        while(i<intervals.size()&&intervals.get(i).start<=newInterval.end){
            newInterval=new Interval(
                Math.min(newInterval.start,intervals.get(i).start),
                Math.max(newInterval.end,intervals.get(i).end)
            );
            i++;
        }
        ans.add(newInterval);
        while(i<intervals.size()&&intervals.get(i).start>newInterval.end){
            ans.add(intervals.get(i++));
        }
        return ans;
    }
}