Given a collection of intervals, merge all overlapping intervals.
For example,
Given
return
Given
[1,3],[2,6],[8,10],[15,18]
,return
[1,6],[8,10],[15,18]
./** * Definition for an interval. * struct Interval { * int start; * int end; * Interval() : start(0), end(0) {} * Interval(int s, int e) : start(s), end(e) {} * }; */ class Solution { static bool compare(Interval & i1, Interval & i2) { return i1.start < i2.start; } public: vector<Interval> merge(vector<Interval>& intervals) { sort(intervals.begin(), intervals.end(), compare); int len = intervals.size(); vector<Interval> res; if(0 == len) return res; res.push_back(intervals[0]); for(int i=1;i<len;i++) { Interval & cur = res[res.size()-1]; if(cur.end >= intervals[i].start) { cur.end = max(cur.end, intervals[i].end); } else { res.push_back(intervals[i]); } } return res; } };