Codility Demo 2 Solution

Codility-demo2.java

//This is 100% marks solution for the demo test PrefixSet https://codility.com/demo/take-sample-test/ps/
import java.util.Hashtable;
class Solution2 {
    public int solution(int[] A) {
        Hashtable<Integer, Integer> map = new Hashtable<>();
        for(int i : A){
            if(map.containsKey(i)){
                map.put(i, map.get(i) +1);
            }else{
                map.put(i, 1);
            }
        }
        for(int i= A.length -1 ; i >=0 ; i--){
            if( map.get(A[i]) > 1){
                continue;
            }else{
                return i;
            }
        }
        return 0;
    }
}