public class practice {

public static void main(String[] args) {

// TODO Auto-generated method stub

//write a program to find the duplicate elements in an array and print the duplicate elements

int[] arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5};

System.out.println(“Duplicate elements in the array are: “);

for(int i=0; i<arr.length; i++) {

for(int j=i+1; j<arr.length; j++) {

if(arr[i] == arr[j]) {

System.out.println(arr[i]);

}

}

}

//write in java8

System.out.println(“Duplicate elements in the array are: “);

java.util.Set<Integer> set = new java.util.HashSet<>();

for(int i=0; i<arr.length; i++) {

if(!set.add(arr[i])) {

System.out.println(arr[i]);

}

}

//write in java8 using stream

System.out.println(“Duplicate elements in the array are: “);

java.util.Map<Integer, Long> map = java.util.Arrays.stream(arr)

.boxed()

.collect(java.util.stream.Collectors.groupingBy(java.util.function.Function.identity(),

java.util.stream.Collectors.counting()));

}

}