Remove Duplicate Element in Array using Temporary Array

An array is an information structure that contains a gathering of components. Commonly these components are the greater part of similar information compose, for example, a whole number or string. Arrays are regularly utilised as a part of PC projects to compose information with the goal that a related arrangement of qualities can be effectively arranged or searched.In java Program to expel copy component in an Array

We can expel copy component in an array by 2 different ways: utilising impermanent array or utilising separate record. To expel the copy component from array, the array must be in arranged request. On the off chance that array isn't arranged, you can sort it by calling Arrays sort strategy.

1) Remove Duplicate Element in Array using Temporary Array

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package prime;

/**
 *
 * @author rajesh kumar shukla
 */

public class RemoveDuplicateArrayExample1{ 
public static int RemoveDuplicateArrayExample1(int arr[], int n){ 
        if (n==0 || n==1){ 
            return n; 
        } 
        int[] temp = new int[n]; 
        int j = 0; 
        for (int i=0; i<n-1; i++){ 
            if (arr[i] != arr[i+1]){ 
                temp[j++] = arr[i]; 
            } 
         } 
        temp[j++] = arr[n-1];   
        // Changing original array 
        for (int i=0; i<j; i++){ 
            arr[i] = temp[i]; 
        } 
        return j; 
    } 
     
    public static void main (String[] args) { 
        int arr[] = {10,20,20,30,30,40,50,50}; 
        int length = arr.length; 
        length = RemoveDuplicateArrayExample1(arr, length); 
        //printing array elements 
        for (int i=0; i<length; i++) 
           System.out.print(arr[i]+" "); 
    } 
} 

2) Remove Duplicate Element in Array using separate index

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package prime;

/**
 *
 * @author rajesh kumar shukla
 */

public class RemoveDuplicateArrayExample2{ 

    public static int removeDuplicateElements(int arr[], int n){ 
        if (n==0 || n==1){ 
            return n; 
        }   
        int j = 0;//for next element 
        for (int i=0; i < n-1; i++){ 
            if (arr[i] != arr[i+1]){ 
                arr[j++] = arr[i]; 
            } 
        } 
        arr[j++] = arr[n-1]; 
        return j; 
    } 
     
    public static void main (String[] args) { 
        int arr[] = {10,20,20,30,30,40,50,50}; 
        int length = arr.length; 
        length = removeDuplicateElements(arr, length); 
        //printing array elements 
        for (int i=0; i<length; i++) 
           System.out.print(arr[i]+" "); 
    } 
} 

3)Remove Duplicate Elements in Unsorted Array

If you have unsorted array, you need to sort it first. To do so, use Arrays.sort(arr) method.
import java.util.Arrays; 
public class RemoveDuplicateInArrayExample3{ 
public static int removeDuplicateElements(int arr[], int n){ 
        if (n==0 || n==1){ 
            return n; 
        } 
        int[] temp = new int[n]; 
        int j = 0; 
        for (int i=0; i<n-1; i++){ 
            if (arr[i] != arr[i+1]){ 
                temp[j++] = arr[i]; 
            } 
         } 
        temp[j++] = arr[n-1];   
        // Changing original array 
        for (int i=0; i<j; i++){ 
            arr[i] = temp[i]; 
        } 
        return j; 
    } 
     
    public static void main (String[] args) { 
        int arr[] = {10,70,30,90,20,20,30,40,70,50};//unsorted array 
        Arrays.sort(arr);//sorting array 
        int length = arr.length; 
        length = removeDuplicateElements(arr, length); 
        //printing array elements 
        for (int i=0; i<length; i++) 
           System.out.print(arr[i]+" "); 
    } 
} 

4)Remove Duplicate 

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package prime;

/**
 *
 * @author rajesh kumar shukla
 */

public class RemoveDuplicateElements
{
public static int[] removeDuplicates(int[] input)
{
int j = 0;
int i = 1;
// return if the array length is less than 2
if (input.length < 2)
{
return input;
}
while (i < input.length)
{
if (input[i] == input[j])
{
i++;
}
else
{
input[++j] = input[i++];
}
}
int[] output = new int[j + 1];
for (int k = 0; k < output.length; k++)
{
output[k] = input[k];
}
return output;
}

public static void main(String a[])
{
int[] input1 = { 2, 3, 6, 6, 8, 9, 10, 10, 10, 12, 12 };
int[] output = removeDuplicates(input1);

System.out.print("Input Elements: \n");
for (int i : input1)
{
System.out.print(i + " ");
}
System.out.print("\nOutput Elements: \n");
for (int i : output)
{
System.out.print(i + " ");
}
}
}

Output

Input Elements:
2 3 6 8 9 10 12 10 10 12 12
Output Elements:
2 3 6 8 9 10 12