LeetCode Insert Interval

/**
 * 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;
bool incmp(struct Interval  a,struct Interval  b)
     {
         return  a.start<b.start;
     }
class Solution {
public:
    void mer(vector<Interval> &v,int &i)
     {
         if(v[i+1].start<=v[i].end)
         {
             if(v[i].end<v[i+1].end)
                 v[i].end=v[i+1].end;
             v.erase((vector<Interval>::iterator)(&v[i+1]));
             i--;
         }
     }
    vector<Interval> insert(vector<Interval> &intervals, Interval newInterval) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        intervals.push_back(newInterval);
        if(intervals.size()<2)
             return intervals;
         sort(intervals.begin(),intervals.end(),incmp);
       
         for(int i=0;i<intervals.size()-1;i++)
         {
             mer(intervals,i);
         }
         return intervals;
    }
};