/*Given an array of random numbers, Push all the zero’s of a given array to the end of the array.

For example, if the given arrays is {1, 9, 8, 4, 0, 0, 2, 7, 0, 6, 0}, it should be changed to

{1, 9, 8, 4, 2, 7, 6, 0, 0, 0, 0}. The order of all other elements should be same. Expected time

complexity is O(n) and extra space is O(1).

*/

public class MoveAllZero {

//This will use O(n^2) time and O(1) space

public int[] moveall (int[] arr){

int[] re = arr;

int i,j;

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

j=0;

if(arr[i]==0){

while(arr[i+j]==0 && i+j<arr.length-1){

j++;

}

int temp = re[i+j];

re[i+j] = arr[i];

re[i] = temp;

}

}

return re;

}

//This will use O(n) time and O(1) space

public int[] moveall (int[] arr){

int[] re = arr;

int i,j;

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

if(arr[i]!=0){

arr[j++] = arr[i];

}

}

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

arr[i] =0;

}

return re;

}

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

int[] arr = {1, 9, 8, 4, 0, 0, 2, 7, 0, 6, 0};

int[] re = arr;

MoveAllZero maz = new MoveAllZero();

re = maz.moveall(arr);

for (int i : re){

System.out.print(i+" ");

}

}

}