Question

I have two arraylists and the second one is a subset of the first.
I want to know the initial and final position in the first arraylist of elements in the subset (in my example the position in arrayList of: uno, due, tre)

How to modify this code?

import java.util.ArrayList;

public class ConfrontaArrayList {
public static void main(String[] args)
{
    ArrayList<String> arrayList = new ArrayList<String>();
    ArrayList<String> subSetArrayList = new ArrayList<String>();

    arrayList.add("inizio");
    arrayList.add("stringa");
    arrayList.add("uno");
    arrayList.add("due");
    arrayList.add("tre");
    arrayList.add("fine");
    arrayList.add("stringa");

    subSetArrayList.add("uno");
    subSetArrayList.add("due");
    subSetArrayList.add("tre");

    System.out.print("Elementi di arrayList: ");
    for (String stringa : arrayList) System.out.print(stringa + " ");
    System.out.print("\nElementi di subSetArrayList: ");
    for (String stringa : subSetArrayList) System.out.print(stringa + " ");
}
}  

Answer 1

java.util.Collections.indexOfSubList() method will return the index of the sub list:

int startIdx = Collections.indexOfSubList(arrayList, subSetArrayList);
if (-1 != startIdx)
{
    int endIdx = startIdx + subSetArrayList.size() - 1;
}