package algorithm.search;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
/**
* The type Duplicates.
*/
public class Duplicates {
/**
* Find duplicates array list.
*
* @param arr the arr
* @return the array list
*/
public static ArrayList findDuplicates(int[] arr) {
ArrayList duplicates = new ArrayList();
Map map = new HashMap();
int count = 0;
for (int i = 0; i < arr.length; i++) {
if (map.containsKey(arr[i])) {
count = map.get(arr[i]);
map.put(arr[i], count + 1);
} else {
map.put(arr[i], 1);
}
}
for (Map.Entry entry : map.entrySet()) {
if (entry.getValue() > 1) {
duplicates.add(entry.getKey());
}
}
return duplicates;
}
/**
* The entry point of application.
*
* @param args the input arguments
*/
public static void main(String[] args) {
int arr[] = {
7,
5,
4,
3,
5,
11,
7,
11,
3,
11
};
ArrayList dupes = findDuplicates(arr);
System.out.println("Duplicates in " + Arrays.toString(arr) + " are " + dupes);
int arr1[] = {
6,
5,
17,
17
};
dupes = findDuplicates(arr1);
System.out.println("Duplicates in " + Arrays.toString(arr1) + " are " + dupes);
}
}