Insert Interval

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]

.

/**
* 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; }
* }
*/
public class Solution {
public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
List<Interval> res = new ArrayList<Interval>();
if (intervals.size() == 0) {
intervals.add(newInterval);
return intervals;
}

int i = 0;
while (i < intervals.size() && intervals.get(i).end < newInterval.start) {
res.add(intervals.get(i));
i++;
}

if (i < intervals.size()) {
newInterval.start = Math.min(intervals.get(i).start, newInterval.start);
}

res.add(newInterval);

while (i < intervals.size() && intervals.get(i).start <= newInterval.end) {
newInterval.end = Math.max(newInterval.end, intervals.get(i).end);
i++;
}
while(i < intervals.size()) {
res.add(intervals.get(i));
i++;
}

return res;
}
}