# Leetcode and alternative solutions

To practice on Leetcode
It has more number of tests in there so I suggest you to have a go:
move-zeros
Note the problem moves the zeros in the other directions.

Two solutions:

1. Storing the position of zero index.

``````class moveZerosToLeft{
static void move_zeros_to_left_in_array(int[] arr) {
int zeroIdx = -1;
for (int i = arr.length - 1; i >= 0; i--) {
if (arr[i] == 0 && zeroIdx == -1) {
zeroIdx = i;
} else if (arr[i] != 0 && zeroIdx != -1){
arr[zeroIdx] = arr[i];
arr[i] = 0;
zeroIdx--;
}
}
}
}
``````

Method 2. storing the position of non-zero index.
This solution is from the leetcode, I think it is very elegant.
This has the same logic as the provided solution but implemented more nicely.

``````class moveZerosToLeft{
static void move_zeros_to_left_in_array(int[] arr) {
for (int nonZeroIdx = arr.length-1, i = arr.length-1; i >=0; i--) {
if (arr[i] != 0) {
if (nonZeroIdx != i) {
int temp = arr[i];
arr[i] = arr[nonZeroIdx];
arr[nonZeroIdx] = temp;
}
nonZeroIdx--;
}
}
}
}
``````

Quick test shows both methods do same number of operations for a given input.
But method 2 is easier to read.

#### Hi @Wonjoon_Seol,

Umer here from the Educative content team. Thanks for sharing these alternate solutions through our platform.