Fest and pesters

class Solution {
  public:
    bool ispossible(vector<int> &time , int NUM , int N , long long int  v)
    {
        long long int c = 0 ; 
        for(int  i = 0 ; i < time.size() ; i++)
        {
           c = c + (v /(long long int)time[i] ) ; 
           
        }
        if(c >= NUM)
        {
            return true ; 
        }
        return false ; 
    }
    long long minimumTime(int N, int NUM, vector<int> &time) {
        // code here
        int m = 1e9  ; 
        for(int i = 0 ; i < time.size() ; i++)
        { 
            m = min(m , time[i]) ;
        }
        long long int l = 1 ; 
        long long int r = m* (long long int)NUM ; 
        long long int  res = r ; 
        while( l <= r)
        {
            
            long long int mid= l + (r - l)/2 ;
            bool a = ispossible(time , NUM , N , mid) ;
            if(a == false )
            {
               l = mid + 1  ;  
            }
            else
            {
              // cout << mid << " "; 
                r = mid - 1; 
                res = min(res , mid) ;
            }
          
        }
        return res;;
    }
};