Leetcode 27. Remove Element

原题：
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 arrayin-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.

解决方法：

跟上一题类似，用一个变量保存不是目标数的位置，遍历数组，当不是目标数时，拷贝该数并将位置往后移动。

代码：

int removeElement(vector<int>& nums, int val) {
int res = 0;
for(int i = 0; i < nums.size(); i++){
if (nums[i] != val){
nums[res++] = nums[i];
}
}
return res;
}