leetcode-56-Merge Intervals

Given a collection of intervals, merge all overlapping intervals.

Example 1:

Input: [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].
Example 2:

Input: [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.

/**
 * 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:
    bool static compare(const Interval &a,const Interval &b){
        return a.start<b.start;
    }
    vector<Interval> merge(vector<Interval>& intervals) {
        sort(intervals.begin(),intervals.end(),compare);
        int i,size = intervals.size();
        for(i=1;i<size;){
            if(intervals[i].start <= intervals[i-1].end){
                intervals[i-1].end = max(intervals[i].end,intervals[i-1].end);
                intervals.erase(intervals.begin() + i);
                size--;
            }
            else{
                i++;
            }
        }
        return intervals;
    }
};