56.cpp

/**
 * 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 {
public:
    vector<Interval> merge(vector<Interval>& intervals) {
        if(intervals.empty())   return vector<Interval>();
        
        //lambda：[capture list] (parameter list) -> return type {function body}
        sort(intervals.begin(),intervals.end(),[](const Interval &i1,const Interval &i2){return i1.start < i2.start;});
        
        vector<Interval> res;
        res.push_back(intervals[0]);
        for(int i = 1;i < intervals.size();i++){
            if(intervals[i].start <= res.back().end)    
                res.back().end = max(intervals[i].end,res.back().end);
            else
                res.push_back(intervals[i]);
        }
        
        return res;
    }
};