Given an array nums and a value val, remove all instances of that value in-place and return the new length.

RemoveElement.cs

public class Solution {
    public int RemoveElement(int[] nums, int val) {
        int len = nums.Length;
        int i = 0;
        int j = 0;
        while(i<len){
            while(i<len && nums[i] == val){
                i++;
            }
            if(i<len){
                nums[j] = nums[i];    
                j++;
            }
            i++;
        }
        return j;        
    }
}