Greedy interval problem (5)

A daily topic ing, Today is a day medium topic 452. Minimum Number of Arrows to Burst Balloons

class Solution {
    
public:
    static bool cmp(vector<int>& a,vector<int>& b)
     {
    
        return a[1]<b[1];
    }
    int findMinArrowShots(vector<vector<int>>& points) 
    {
    
        sort(points.begin(),points.end(),cmp);
        int num=0,i=0,flag=0;
        while(i<points.size())
        {
    
            int right=points[i][1];
            flag=1;
            int j;
            for(j=i+1;j<points.size();j++)
            {
    
                if(right<points[j][0])
                {
    
                    i=j;
                    break;
                }
            }     
            i=j;
            if(flag==1)   
                num++;
        }    
        return num;
    }
};