[Leetcode] 57. 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; }
* }
*/
import java.util.ArrayList;
public class Solution {
public ArrayList<Interval> insert(ArrayList<Interval> intervals, Interval newInterval) {
ArrayList<Interval> result = new ArrayList<Interval>();
if(intervals == null || newInterval == null) return result;
int insertPosition = 0;
for(Interval interval: intervals){
if(interval.end < newInterval.start){
result.add(interval);
insertPosition++;
} else if(interval.start > newInterval.end){
result.add(interval);
} else {
newInterval.start = Math.min(newInterval.start, interval.start);
newInterval.end = Math.max(newInterval.end, interval.end);
}
}
result.add(insertPosition, newInterval);
return result;
}
}