fork download 
  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Ideone
  9. {
  10. 	public static void main (String[] args) throws java.lang.Exception
  11. 	{
  12. 		Scanner sc = new Scanner(System.in);
  13. 		int n = sc.nextInt();
  14. 		int arr[] = new int[n];
  15. 		for(int i=0;i<n;i++){
  16. 			arr[i]=sc.nextInt();
  17. 		}
  18. 		Map<Integer,Integer> mp = new HashMap<>();
  19. 		for(int i=0;i<n;i++){
  20. 			mp.put(arr[i],mp.getOrDefault(arr[i],0)+1);
  21. 		}
  22. 		int noOfTrips = 0;
  23. 		for(int i:mp.keySet()){
  24. 			if(mp.get(i)==1){
  25. 				noOfTrips=-1;
  26. 				break;
  27. 			}
  28. 			noOfTrips = noOfTrips + (mp.get(i)/3);
  29. 			if(mp.get(i)%3!=0){
  30. 				noOfTrips++;
  31. 			}
  32. 		}
  33. 		System.out.println(noOfTrips);
  34. 	}
  35. }
Success #stdin #stdout 0.14s 56464KB
comments (?)
stdin 
7
1 8 5 8 5 1 1
stdout 
3
https://ideone.com/Bu7nYz
language:
Java (HotSpot 12)
created:
17 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!