56. Merge Intervals

/**
 * 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 {
private:
    static bool compareInterval(Interval i1, Interval i2) {
        return (i1.start < i2.start);
    }
public:
    vector<Interval> merge(vector<Interval>& intervals) {
        vector<Interval> ret;
        if(intervals.size() ==0){
            return ret;
        }
        sort(intervals.begin(),intervals.end(),compareInterval);
        ret.push_back(intervals[0]);
        for(int i=1;i<intervals.size();++i) {
            if(ret.back().end >= intervals[i].start){
                ret.back().end = max(ret.back().end,intervals[i].end);
            } else {
                ret.push_back(intervals[i]);
            }
        }
        return ret;
    }
};

• http://www.cnblogs.com/grandyang/p/4370601.html