Merge Intervals***

 1 /**
 2  * Definition for an interval.
 3  * struct Interval {
 4  *     int start;
 5  *     int end;
 6  *     Interval() : start(0), end(0) {}
 7  *     Interval(int s, int e) : start(s), end(e) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     static bool compare(Interval &interval1, Interval &interval2){
13         return interval1.start < interval2.start;
14     }
15     vector<Interval> merge(vector<Interval>& intervals) {
16         vector<Interval> result;
17         if(intervals.size() == 0) return result;
18         if(intervals.size() == 1) return intervals;
19         
20         sort(intervals.begin(), intervals.end(), Solution::compare);
21         Interval inter(intervals[0].start, intervals[0].end);
22         for(int i = 1; i < intervals.size(); i++){
23             if(inter.end < intervals[i].start){
24                 result.push_back(inter);
25                 inter.start = intervals[i].start;
26                 inter.end = intervals[i].end;
27             }
28             else{
29                 inter.start = min(inter.start, intervals[i].start);
30                 inter.end = max(inter.end, intervals[i].end);
31             }
32         }
33         result.push_back(inter);
34         return result;
35     }
36 };