/** * Definition of Interval: * class Interval { * public: *     int start, end; *     Interval(int start, int end) { *         this->start = start; *         this->end = end; *     } * } */class Solution {public:    int minMeetingRooms(vector<Interval>& intervals) {        sort(intervals.begin(), intervals.end(), [](const Interval &a, const Interval &b){            return a.end < b.end;        });        int totalIntervals = intervals.size();        if(totalIntervals == 0) return 0;        int daysReq = 1;        int lastPointer = 0;        for(int intervalIdx = 1; intervalIdx < totalIntervals; intervalIdx++){            Interval interval = intervals[intervalIdx];            if(interval.start < intervals[lastPointer].end){                daysReq++;            }else{                lastPointer++;            }        }        return daysReq;    }};