union of two array

Write a program to union two arrays

import java.util.Scanner;

import java.util.Arrays;

public class UnionTwoArray {

public static void main(String[] args) {

System.out.println("For First Array : ");

int[] arr1=inputArray();

System.out.println("For Second Array : ");

int[] arr2=inputArray();

int[] arr3=mergeSort(arr1, arr2);

int []arr4=removeDuplicates(arr3);

displayArray(arr4);

}

static int[] inputArray() {

Scanner sc=new Scanner(System.in);

System.out.println("Enter Size of Array : ");

int n=sc.nextInt();

int count=0;

int arr[]=new int[n];

System.out.println("enter value in array : ");

for (int i=0; i<n; i++) {

arr[i]=sc.nextInt();

}

return arr;

}

static int[] mergeSort(int a[],int b[]) {

int c[]=new int[a.length+b.length];

int i=0,j=0,k=0;

while(i<a.length && j<a.length) {

if(a[i]<b[j] || a[i]==b[j]) {

c[k++]=a[i++];

}

else if(a[i]!=b[j]) {

c[k++]=b[j++];

}

}while(i<a.length) {

c[k++]=a[i++];

}

while(j<b.length) {

c[k++]=b[j++];

}

return c;

}

static int[] removeDuplicates(int []arr){

   int dup=countDuplicate(arr);

int [] k = new int[arr.length-dup];

    k[0]=arr[0];

    int m =1;

    for(int i=1;i<arr.length;++i){

        if(arr[i]!=arr[i-1]){

            k[m]=arr[i];

            ++m;

        }

    }

    return k;

} 

static void displayArray(int arr[]) {

System.out.println("Array is :\n");

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

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

if(i!=arr.length-1)

System.out.print(",");

}

}

static int countDuplicate(int arr[]) {

int count=0;

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

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

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

count ++;

}

} return count;

}

}