Removing all zeroes to the left of an array GFG

 package com.company;

import java.util.Arrays;

public class Array7 {
//    Sir's efficient method
    public static int[] atEnding(int[] arr){
        int n = arr.length;
        int count = 0;
        for(int i = 0; i < n; i++){
            if(arr[i] != 0){
                arr[count] = arr[i];
                arr[i] = 0;
                count++;
            }
        }
        return arr;
    }
    //    Efficient Solution my solution which takes BIG O(n^2)
    public static int[] atEnd(int[] arr) {
        int n = arr.length;
        int res = 0;
        for (int j = 0; j < n; j++) {
            if (arr[j] == 0) {
                res = j;
                break;
            }
        }
        for (int i = 0; i < n - 1; i++) {
            if (arr[i] == 0 && arr[i + 1] != 0) {
                arr[res] = arr[i + 1];
                arr[i + 1] = 0;
                res = i + 1;
            }
        }
        return arr;
    }

    //    Remove all zero to end MY SOLUTION BIG O(n^2) time
    public static int[] removeZeroToEnd(int[] arr, int n) {
        for (int i = 0; i < n - 1; i++) {
            for (int j = i + 1; j < n; j++) {
                if (arr[i] == 0 && arr[j] != 0) {
//                    int a = arr[i];
                    arr[i] = arr[j];
                    arr[j] = 0;
                }
            }
        }
        return arr;
    }

    public static void main(String[] args) {
        int[] array = {0, 0, 0, 1, 0};
        System.out.println(Arrays.toString(atEnding(array)));
    }
}