移出元素 Remove Element

本文介绍了一种在数组中就地移除指定值的方法,并返回新的有效长度。该算法利用双指针技术,不使用额外空间且允许改变剩余元素的顺序。示例中给出了具体的C++实现。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

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.

Hint:

  1. Try two pointers.
  2. Did you use the property of "the order of elements can be changed"?
  3. What happens when the elements to remove are rare?
跟http://blog.youkuaiyun.com/gao1440156051/article/details/51743374  这题题类似

class Solution {
public:
	int removeElement(vector<int>& nums, int val) {
		int len = nums.size();

		int i = -1;
		for (int j = 0; j < len; j++){
			if (nums[j] != val){
				swap(nums[++i], nums[j]);
			}
		}

		return i + 1;
	}
};


评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值