LeetCode 57

57. Insert Interval

• 题目描述
• 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].

• 解题思路
  线性遍历一遍数组，找出一个最大的覆盖区间

• 代码如下

public class Solution {
    public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
        int len = intervals.size();
        int left = 0;
        int right = len - 1;
        while (left < len && newInterval.start > intervals.get(left).end) {
            left++;
        }
        while (right >= 0 && newInterval.end < intervals.get(right).start) {
            right--;
        }
        if(left == len){
            intervals.add(len,newInterval);
        }else if(right == -1){
            intervals.add(0,newInterval);
        }else if(left <= right){
            newInterval.start = newInterval.start<intervals.get(left).start?newInterval.start:intervals.get(left).start;
            newInterval.end = newInterval.end>intervals.get(right).end?newInterval.end:intervals.get(right).end;
            for(int i=left;i<=right;i++){
                intervals.remove(left);
            }
            intervals.add(left,newInterval);
        }else{
            intervals.add(left,newInterval);
        }
        return intervals;
    }
}