14. Remove Element
Given an array nums and a value val, remove every occurrence of val in place and return the number of remaining elements.
範例 1:
輸入： nums = [3,2,2,3], val = 3 輸出： 2
範例 2:
輸入： nums = [0,1,2,2,3,0,4,2], val = 2 輸出： 5
限制條件：
0 <= nums.length <= 1000 <= val <= 50