import java.util.Set;
import java.util.HashSet;
import java.util.Arrays;
class Main {
public static void main(String[] args) {
int[] array = {2, 5, 1, 2, 3, 5, 1, 2, 4};
System.out.println("First recurring character from array " + Arrays.toString(array) + " is " + firstRecurringCharacter(array));
array = new int[] {2, 1, 1, 2, 3, 5, 1, 2, 4};
System.out.println("First recurring character from array " + Arrays.toString(array) + " is " + firstRecurringCharacter(array));
array = new int[] {2, 3, 4, 5};
System.out.println("First recurring character from array " + Arrays.toString(array) + " is " + firstRecurringCharacter(array));
}
public static Integer firstRecurringCharacter(int[] characters) {
Set<Integer> charactersFound = new HashSet<>();
for (int character : characters) {
if (charactersFound.contains(character)) {
return character;
} else {
charactersFound.add(character);
}
}
return null;
}
}
