LeetCode——移除元素

题目地址：https://leetcode-cn.com/problems/remove-element/

解题思路：设置新的下标

class Solution {
 public:
     int removeElement(vector<int>& nums, int val) {
         if (nums.size() == 0)
             return 0;
         int  idx=0;
         for (int i = 0; i < nums.size(); i++) {
             if (nums[i] == val) {
                 for (; i < nums.size() && nums[i] == val; i++) {}
                 i--;
             }
             else 
                 nums[idx++] = nums[i];
         }
         return idx;
     }
 };