LeetCode27. Remove Element
题目：
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 by modifying the input array in-place with O(1) extra memory.
The order of elements can be changed. It doesn't matter what you leave beyond the new length.
Example:
Given nums = [3,2,2,3], val = 3, Your function should return length = 2, with the first two elements of nums being 2.
代码：
class Solution {
public:
int removeElement(vector<int>& nums, int val) {
for (int i = 0; i < nums.size(); i++) {
if (nums[i] == val) {
nums.erase(nums.begin() + i);
i--;
}
}
return nums.size();
}
};