[leetcode]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:

Input: intervals = [[1,3],[6,9]], newInterval = [2,5]
Output: [[1,5],[6,9]]

Example 2:

Input: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
Output: [[1,2],[3,10],[12,16]]
Explanation: Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10].

题意：

给定一堆区间，插入一个新区间。

Solution1：Sort

code

/**
 * 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 ArrayList<Interval>();
        for (Interval i : intervals) {
            if (newInterval == null || i.end < newInterval.start)
                result.add(i);
            else if (i.start > newInterval.end) {
                result.add(newInterval);
                result.add(i);
                newInterval = null;
            } else {
                newInterval.start = Math.min(newInterval.start, i.start);
                newInterval.end = Math.max(newInterval.end, i.end);
            }
        }
        if (newInterval != null)
            result.add(newInterval);
        return result;
    }
}

改版了新的signature之后：