## Algorithm

Problem - Remove Element

Level - Beginner

Details -

Given an integer array `nums` and an integer `val`, remove all occurrences of `val` in `nums` in-place. The relative order of the elements may be changed.

Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array `nums`. More formally, if there are `k` elements after removing the duplicates, then the first `k` elements of `nums` should hold the final result. It does not matter what you leave beyond the first `k` elements.

Return `k` after placing the final result in the first `k` slots of `nums`.

Do not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.

Custom Judge:

The judge will test your solution with the following code:

```int[] nums = [...]; // Input array
int val = ...; // Value to remove
int[] expectedNums = [...]; // The expected answer with correct length.
// It is sorted with no values equaling val.

int k = removeElement(nums, val); // Calls your implementation

assert k == expectedNums.length;
sort(nums, 0, k); // Sort the first k elements of nums
for (int i = 0; i < actualLength; i++) {
assert nums[i] == expectedNums[i];
}
```

If all assertions pass, then your solution will be accepted.

Example 1:

```Input: nums = [3,2,2,3], val = 3
Output: 2, nums = [2,2,_,_]
Explanation: Your function should return k = 2, with the first two elements of nums being 2.
It does not matter what you leave beyond the returned k (hence they are underscores).
```

Example 2:

```Input: nums = [0,1,2,2,3,0,4,2], val = 2
Output: 5, nums = [0,1,4,0,3,_,_,_]
Explanation: Your function should return k = 5, with the first five elements of nums containing 0, 0, 1, 3, and 4.
Note that the five elements can be returned in any order.
It does not matter what you leave beyond the returned k (hence they are underscores).
```

Constraints:

• `0 <= nums.length <= 100`
• `0 <= nums[i] <= 50`
• `0 <= val <= 100`

## Code Examples

### #1 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
/**
* @param {number[]} nums
* @param {number} val
* @return {number}
*/
var removeElement = function(nums, val) {
let i = 0;
while (i  <  nums.length) {
if (nums[i] === val) {
nums.splice(i, 1);
} else {
++i;
}
}
};
``````
Copy The Code &

Input

cmd
[0,1,2,2,3,0,4,2]
2

Output

cmd
5

### #2 Code Example with C Programming

```Code - C Programming```

``````
int removeElement(int* nums, int numsSize, int val) {
int i, j;
i = 0;
while (i  <  numsSize && nums[i] != val) i ++;
for (j = i + 1; j  <  numsSize; j ++) {
if (nums[j] != val) {
nums[i ++] = nums[j];
}
}
return i;
}

``````
Copy The Code &

Input

cmd
[3,2,2,3]
3

Output

cmd
2

### #3 Code Example with C++ Programming

```Code - C++ Programming```

``````
class Solution {
public:
int removeElement(vector<int>& nums, int val) {
int i = 0, j = 0;
while(j != nums.size())
if(nums[j] == val) j++;
else nums[i++] = nums[j++];
return i;
}
};
``````
Copy The Code &

Input

cmd
[0,1,2,2,3,0,4,2]
2

Output

cmd
5

### #4 Code Example with C# Programming

```Code - C# Programming```

``````
namespace LeetCode
{
public class _027_RemoveElement
{
public int RemoveElement(int[] nums, int val)
{
var lastIndex = nums.Length - 1;

for (int i = 0; i  < = lastIndex; i++)
{
if (nums[i] == val)
{
nums[i--] = nums[lastIndex--];
}
}

return lastIndex + 1;
}
}
}
``````
Copy The Code &

Input

cmd
[3,2,2,3]
3

Output

cmd
2

### #5 Code Example with Java Programming

```Code - Java Programming```

``````
public int removeElement(int[] nums, int val) {
int idx = 0;
for (int i = 0; i  <  nums.length; i++) {
if (nums[i] != val) {
nums[idx++] = nums[i];
}
}
return idx;
}
}
``````
Copy The Code &

Input

cmd
[0,1,2,2,3,0,4,2]
2

Output

cmd
5

### #6 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def removeElement(self, nums: List[int], val: int) -> int:
i = 0
for num in nums:
if num != val:
nums[i] = num
i += 1
return i
``````
Copy The Code &

Input

cmd
[0,1,2,2,3,0,4,2]
2

Output

cmd
5