LeetCode 27. Remove Element

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

Do not allocate extra space for another array, you must do this in place with constant memory.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Example:
Given input array nums = [3,2,2,3], val = 3

Your function should return length = 2, with the first two elements of nums being 2.

注：vector的erase操作，经过nums.erase(i)以后，迭代器已经指向下一个元素，此时不能再对迭代器i进行自加操作，否则会跳过下一个元素。

class Solution {public:    int removeElement(vector<int>& nums, int val)    {        int n = nums.size();        int length = n;        vector<int>::iterator i = nums.begin();        while(i != nums.end())        {            if(*i == val)            {                nums.erase(i);                length--;            }            else            {               i++;              }                   }        return length;               }};