Counting the equal elements in arraylist

Question

This is my code

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package javaapplication1;

import static com.sun.org.apache.xalan.internal.lib.ExsltStrings.split;
import static java.rmi.Naming.list;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import static java.util.Collections.list;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 *
 * @author dhanushka
 */
public class JavaApplication1 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

        String s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
       // String s = "ABCDE";
       String[] strValues = s.split("");

       ArrayList<String> aListNumbers = new ArrayList<String>(Arrays.asList(strValues));
       //System.out.println("Java String converted to ArrayList: " + aListNumbers);
       aListNumbers.remove(0);
       //System.out.println("Java String converted to ArrayList: " + aListNumbers);
       if(aListNumbers.size()%2==1) {
         aListNumbers.add("");
       }

       List<List<String>> list = new ArrayList<List<String>>();

       for (int x = 0;x<aListNumbers.size()-1;x++) {
           List<String> l = new ArrayList<String>();
           l.add(aListNumbers.get(x));
           l.add(aListNumbers.get(x+1));
           list.add(l);
           x++;
       }

       System.out.println("List "+list);
       // System.out.println("List "+list.toString());
    }   
}

OUTPUT run:

List [[H, B], [V, R], [7, R], [A, T], [F, C], [H, E], [G, J], [3, 1], [2, Z], [K, S], [7, D], [1, 4], [X, 6], [9, 7], [7, Q], [O, N], [S, G], [J, Y], [U, K], [7, S], [U, 5], [V, F], [8, R], [D, O], [O, X], [2, 9], [A, F], [J, D], [J, 1], [3, B], [R, C], [W, Z], [Y, 3], [W, 9], [9, E], [G, S], [1, 1], [8, C], [S, W], [5, G], [3, V], [T, J], [Y, P], [N, N], [7, G], [P, 3], [Q, 6], [B, S], [I, 6], [R, E], [5, D], [O, J], [R, K], [H, J], [G, G], [V, X], [6, X], [H, 6], [S, M], [B, I], [Q, J], [C, 2], [Y, N], [B, 5], [0, Q], [4, V], [E, 0], [L, 0], [G, J], [2, O], [H, D], [G, 0], [V, 2], [7, 3], [Z, F], [9, 6], [5, I], [X, V], [B, W], [V, D], [I, M], [S, 0], [M, 9], [S, F], [M, Q], [Z, J], [T, X], [B, N], [C, L], [H, 6], [P, I], [G, V], [Q, 7], [0, 6], [C, Z], [Y, U], [Y, Z], [F, 5], [V, P], [N, V], [J, 1], [Q, I], [P, Z], [M, I], [H, K], [S, Z], [O, Z], [Y, A], [G, 7], [J, O], [I, W], [C, W], [2, E], [V, 4], [R, G], [1, X], [7, V], [W, Y], [1, 7], [F, 1], [U, S], [Y, 1], [G, 9], [F, 8], [B, F], [Z, X], [F, 9], [N, X], [Y, 4], [Q, L], [E, S], [0, A], [S, 5], [1, 3], [C, 9], [J, I], [2, S], [4, Z], [7, L], [P, 2], [8, W], [3, M], [R, E], [R, 8], [I, 9], [9, 6], [R, 4], [W, C], [2, X], [I, L], [H, M], [6, B], [5, Q], [5, W], [E, X], [Z, N], [O, X], [M, S], [Y, N], [T, O], [N, 3], [U, D], [A, M], [0, 8], [6, 1], [7, J], [C, E], [V, V], [Z, 2], [Q, A], [J, 4], [3, U], [K, V], [S, 4], [R, E], [N, O], [E, 4], [7, O], [2, 2], [A, T], [0, 6], [0, N], [Z, P], [L, K], [B, 0], [2, 6], [7, T], [E, T], [9, 9], [3, P], [3, 6], [Q, 2], [N, T], [F, H], [G, H], [3, 7], [2, 7], [J, M], [D, Q], [4, 4], [J, H], [2, 0], [L, R], [R, U], [Z, O], [O, 2], [9, U], [Z, 4], [Q, 8], [9, G], [J, D], [E, 4], [6, 5], [E, A], [J, 2], [P, T], [E, 8], [F, W], [D, 0], [Q, 6], [C, V], [S, 1], [2, B], [7, H], [H, P], [6, F], [Q, Y], [U, G], [D, 7], [3, Q], [M, Q], [K, 6], [9, 5], [X, A], [P, D], [0, 0], [S, D], [E, Y], [V, M], [B, 5], [7, 6], [2, 3], [6, J], [C, Q], [O, 9], [S, G], [6, A], [T, V], [K, V], [1, Y], [6, C], [0, M], [D, G], [X, N], [U, 6], [U, 0], [6, 8], [S, P], [Y, Q], [A, Z], [2, G], [W, Q], [V, U], [3, S], [T, S], [N, A], [V, E], [Q, A], [F, Y], [E, 0], [W, Z], [6, R], [O, 2], [J, 8], [R, D], [7, 3], [U, C], [E, I], [K, L], [S, F], [M, F], [3, B], [S, U], [F, 1], [Y, 6], [C, 0], [M, D], [D, C], [K, E], [B, 3], [K, 5], [A, Q], [V, U], [P, T], [9, I], [0, 3], [G, 8], [O, R], [6, 5], [9, 4], [W, S], [Q, 9], [2, 7], [Q, K], [9, C], [7, G], [K, Z], [5, Q], [E, M], [P, 7], [F, W], [1, J], [2, R], [3, O], [5, V], [G, P], [E, H], [G, 1], [P, B], [X, Y], [D, E], [T, 7], [K, T], [S, Q], [D, 7], [N, T], [P, B], [Z, A], [0, G], [H, K], [E, C], [O, N], [5, S], [B, D], [T, D], [B, C], [Z, 1], [4, A], [C, 4], [8, I], [9, M], [L, 8], [H, W], [9, C], [S, G], [B, I], [4, M], [T, B], [Z, G], [B, 2], [S, P], [7, 9], [5, L], [4, Y], [H, Y], [7, 6], [H, 8], [L, 1], [0, Q], [F, J], [S, 8], [U, N], [C, 2], [H, M], [H, 2], [K, 6], [2, G], [Z, T], [P, M], [D, 6], [2, L], [5, 3], [I, F], [A, 5], [A, 2], [L, J], [A, 2], [J, U], [4, U], [7, D], [D, R], [Q, P], [N, B], [D, B], [J, 2], [L, O], [N, I], [R, G], [D, 1], [E, 6], [1, L], [M, P], [R, B], [5, A], [7, F], [Y, 5], [O, 9], [3, K], [5, P], [P, G], [B, 9], [W, I], [Q, 6], [6, 1], [L, C], [Q, D], [P, A], [L, 1], [F, A], [8, M], [G, D], [E, D], [E, Q], [9, N], [P, G], [L, X], [L, 8], [5, 2], [Z, D], [9, U], [E, D], [Y, 4], [Y, U], [Q, O], [Y, C], [F, 4], [R, D], [9, 8], [5, S], [E, Y], [6, C], [0, M], [D, 2], [2, Q], [F, S], [B, B], [B, N], [H, C], [O, J], [P, T], [A, V], [Y, N], [A, Q], [G, H], [8, 6], [7, G], [9, 9], [X, V], [1, T], [D, 6], [2, 9], [J, F], [A, D], [3, D], [6, 7], [U, V], [D, U], [9, M], [4, 9], [E, K], [W, U], [R, J], [V, 5], [B, B], [0, V], [L, 4], [F, T], [0, A], [L, S], [M, 6], [W, D], [K, B], [M, L], [C, O], [A, K], [0, 2], [P, 3], [J, H], [R, A], [U, F], [B, 2], [M, K], [V, Z], [Q, U], [4, 8], [A, M], [W, H], [X, S], [J, Q], [7, K], [2, X], [B, P], [4, T], [P, M], [J, T], [T, L], [8, H], [4, 4], [1, A], [P, W]] BUILD SUCCESSFUL (total time: 1 second)

I want to get count of equal elements in last list

Answer 1

This code will count the number of equal lists in your list.

 Set<String> set = new HashSet<>();
    int count = 0;
    for (ArrayList<String> list : lists) {
        String s = list.get(0) + list.get(1);
        if (set.contains(s)) {
            count++;
        } else {
            set.add(s);
        }
    }
    System.out.println("equal elemets: " + count);

Answer 2

Your code splits the original string into groups of 2 consecutive characters.

If you want to check if those 2 consecutive characters are equal, you can do:

char[] chars = s.toCharArray();
int count = 0;
for(int i = 0 ; i < chars.length - 1 ; i += 2) {
    count += chars[i] == chars[i+1] ? 1 : 0;
}