Leet Code: Move the zeros to the last of the given int[] while maintaining the relative order of the non zero numbers.

moveZeros.java

class Solution {
    public void moveZeroes(int[] nums) {
        var len = nums.length;
        var mark = 0;
        for (int i = 0; i < len; i++){
            if (nums[i] != 0){
                nums[mark] = nums[i];
                mark++;
            } 
        }
        for (int j = mark; j < len; j++){
            nums[j] = 0;
        }        
    }
}

Observation

The above problem was solved using two approaches by me and the most optimal solution was found online.

Approach 1

• get the next zero location
• get the next non-zero location
• swap them.
• repeat till the next non-zero location is equal to the length of the array given.

This approach beats 12% of the total solutions submitted with a runtime of 30 ms.

Approach 2

• iterate through the array
• if the current value is non zero updates the marker by one else don't update
• if the current value is non-zero and the iterator and marker are not the same then swap nums.

The above approach beats 42% of the total solutions submitted with a runtime of 2 ms.

Approach 3

• iterate through the array
• if the current value is non-zero then update the marker location with the value and update the marker.
• after iteration is complete. iterate from the marker position to the last making the values as 0.

The above approach beats 100% of the cases with a runtime of 1 ms.

A link to all the submissions. Click here