CODE 76. Insert Interval

版权声明：本文为博主原创文章，转载请注明出处，谢谢!

版权声明：本文为博主原创文章，转载请注明出处：http://blog.jerkybible.com/2013/10/11/2013-10-11-CODE 76 Insert Interval/

访问原文「CODE 76. 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].

public ArrayList<Interval> insert(ArrayList<Interval> intervals,
		Interval newInterval) {
	// Note: The Solution object is instantiated only once and is reused by
	// each test case.
	if (null == intervals || intervals.isEmpty()) {
		ArrayList<Interval> newIntervals = new ArrayList<Interval>();
		if (null != newInterval) {
			newIntervals.add(newInterval);
		}
		return newIntervals;
	}
	int i;
	for (i = 0; i < intervals.size(); i++) {
		if (newInterval.start >= intervals.get(i).start
				&& newInterval.start <= intervals.get(i).end
				&& newInterval.end >= intervals.get(i).end) {
			intervals.get(i).end = newInterval.end;
			break;
		} else if (newInterval.end >= intervals.get(i).start
				&& newInterval.end <= intervals.get(i).end
				&& newInterval.start <= intervals.get(i).start) {
			intervals.get(i).start = newInterval.start;
			break;
		} else if (newInterval.start >= intervals.get(i).start
				&& newInterval.end <= intervals.get(i).end) {
			return intervals;
		} else if (newInterval.start <= intervals.get(i).start
				&& newInterval.end >= intervals.get(i).end) {
			intervals.get(i).start = newInterval.start;
			intervals.get(i).end = newInterval.end;
			break;
		} else if (newInterval.end < intervals.get(i).start) {
			intervals.add(i, newInterval);
			break;
		}
	}
	if (i >= intervals.size()) {
		intervals.add(newInterval);
		return intervals;
	}
	ArrayList<Interval> newIntervals = new ArrayList<Interval>();
	Interval first = intervals.get(0);
	for (i = 1; i < intervals.size(); i++) {
		if (null == first) {
			first = intervals.get(i);
		} else if (intervals.get(i).start >= first.start
				&& intervals.get(i).start <= first.end
				&& intervals.get(i).end >= first.end) {
			first.end = intervals.get(i).end;
		} else if (intervals.get(i).end >= first.start
				&& intervals.get(i).end <= first.end
				&& intervals.get(i).start <= first.start) {
			first.start = intervals.get(i).start;
		} else if (intervals.get(i).start >= first.start
				&& intervals.get(i).end <= first.end) {
			continue;
		} else if (intervals.get(i).start <= first.start
				&& intervals.get(i).end >= first.end) {
			first.start = intervals.get(i).start;
			first.end = intervals.get(i).end;
		} else {
			newIntervals.add(first);
			first = null;
			first = intervals.get(i);
		}
	}
	if (null != first) {
		newIntervals.add(first);
	}
	return newIntervals;
}