leetcode_c++：Remove Element (027)

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 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

算法

设置两个指针，一个为可以放位置的指针，一个是扫描指针

复杂度

O(N)

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

        }

        return ret;

    }
};