// https://www.hackerrank.com/challenges/java-hashset/problem import java.util.HashSet; import java.util.Objects; import java.util.Scanner; import java.util.Set; public class JavaHashset { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int queries = scanner.nextInt(); Set set = new HashSet<>(); while (queries-- > 0) { String first = scanner.next(); String second = scanner.next(); Pair pair = new Pair(first, second); set.add(pair); System.out.println(set.size()); } } private static class Pair { private final String first; private final String second; Pair(String first, String second) { this.first = first; this.second = second; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Pair pair = (Pair) o; return Objects.equals(first, pair.first) && Objects.equals(second, pair.second); } @Override public int hashCode() { return Objects.hash(first, second); } } }