[LeetCode] 27. Remove Element

题目链接：传送门

Description

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.

Solution

题意：

给定一个数组，去掉数组中的特定值，注意 in-place

思路：

理解 in-place，直接做

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