Removing duplicates from an array

 package com.company;

import java.util.Arrays;

public class Array6 {
    //    Efficient method
    public static int remove(int[] arr, int n) {
        int res = 1;
        for (int i = 1; i < n; i++) {
            if (arr[i] != arr[res - 1]) {
                arr[res] = arr[i];
                res++;
            }
        }
        return res;
    }

    //    Naive method
    public static int remDuplicates(int[] arr, int n) {
        int[] temp = new int[n];
        temp[0] = arr[0];
        int res = 1;

        for (int i = 1; i < n; i++) {
            if (arr[i] != temp[res - 1]) {
                temp[res] = arr[i];
                res++;
            }
        }
        for (int j = 0; j < res; j++) {
            arr[j] = temp[j];
        }
        return res;
    }

    //    Removing duplicates element from a sorted array my solution
    public static int removeDuplicate(int[] arr, int n) {
        int count = 0;
        int res = 0;
        int a = 0;
        if (n == 1) {
            return 1;
        }
        for (int i = 0; i < n - 1; i++) {
            if (arr[i] != arr[res] || a == 0) {
                for (int j = i + 1; j < n; j++) {
                    if (arr[i] == arr[j]) {
                        res = j;
                        count++;
                        a++;
                    }
                }
            }
        }
        return (n - count);
    }

    public static void main(String[] args) {
        int[] array = {10, 56, 78, 98, 98, 100, 100};
        System.out.println(remove(array, 7));
    }
}