C. Basketball Exercise

time limit per test

2 seconds

memory limit per test

256 megabytes

Finally, a basketball court has been opened in SIS, so Demid has decided to hold a basketball exercise session. 2⋅n2⋅n students have come to Demid's exercise session, and he lined up them into two rows of the same size (there are exactly nn people in each row). Students are numbered from 11 to nn in each row in order from left to right.

Now Demid wants to choose a team to play basketball. He will choose players from left to right, and the index of each chosen player (excluding the first one taken) will be strictly greater than the index of the previously chosen player. To avoid giving preference to one of the rows, Demid chooses students in such a way that no consecutive chosen students belong to the same row. The first student can be chosen among all 2n2n students (there are no additional constraints), and a team can consist of any number of students.

Demid thinks, that in order to compose a perfect team, he should choose students in such a way, that the total height of all chosen students is maximum possible. Help Demid to find the maximum possible total height of players in a team he can choose.

Input

The first line of the input contains a single integer nn (1≤n≤1051≤n≤105) --- the number of students in each row.

The second line of the input contains nn integers h1,1,h1,2,...,h1,nh1,1,h1,2,...,h1,n (1≤h1,i≤1091≤h1,i≤109), where h1,ih1,i is the height of the ii-th student in the first row.

The third line of the input contains nn integers h2,1,h2,2,...,h2,nh2,1,h2,2,...,h2,n (1≤h2,i≤1091≤h2,i≤109), where h2,ih2,i is the height of the ii-th student in the second row.

Output

Print a single integer --- the maximum possible total height of players in a team Demid can choose.

Examples

Input

Copy

复制代码
5
9 3 5 7 3
5 8 1 4 5

Output

Copy

复制代码
29

Input

Copy

复制代码
3
1 2 9
10 1 1

Output

Copy

复制代码
19

Input

Copy

复制代码
1
7
4

Output

Copy

复制代码
7

Note

In the first example Demid can choose the following team as follows:

In the second example Demid can choose the following team as follows:

解题说明:此题是一道动态规划题,两排运动员的身高,选出运动员使总身高最大(不能出现有两个运动员是连续痛一排的,只能挨着的两个运动员是不同排位的),输出得到的最大总身高,直接按照DP算法进行求解。

cpp 复制代码
#include<stdio.h>
#include<string.h>
long long int max(long long int a, long long int b)
{
	if (a > b)
	{
		return a;
	}
	else
	{
		return b;
	}
}

int main()
{
	int n;
	scanf("%d", &n);
	long long int h[2][100005];
	for (int i = 0; i < n; i++)
	{
		scanf("%lld", &h[0][i]);
	}
	for (int i = 0; i < n; i++)
	{
		scanf("%lld", &h[1][i]);
	}
	long long int dp[3][n];

	memset(dp, 0, sizeof(dp));
	dp[0][0] = h[0][0];
	dp[1][0] = h[1][0];
	dp[2][0] = 0;

	for (int i = 1; i < n; i++)
	{
		dp[0][i] = max(dp[1][i - 1] + h[0][i], dp[2][i - 1] + h[0][i]);
		dp[0][i] = max(dp[0][i], h[0][i]);

		dp[1][i] = max(dp[0][i - 1] + h[1][i], dp[2][i - 1] + h[1][i]);
		dp[1][i] = max(dp[1][i], h[1][i]);

		dp[2][i] = max(dp[0][i - 1], dp[1][i - 1]);
	}
	printf("%lld\n", max(dp[0][n - 1], dp[1][n - 1]));
	return 0;
}
相关推荐
西阳未落4 小时前
C++基础(21)——内存管理
开发语言·c++·面试
我的xiaodoujiao4 小时前
Windows系统Web UI自动化测试学习系列2--环境搭建--Python-PyCharm-Selenium
开发语言·python·测试工具
callJJ4 小时前
从 0 开始理解 Spring 的核心思想 —— IoC 和 DI(2)
java·开发语言·后端·spring·ioc·di
超级大福宝4 小时前
使用 LLVM 16.0.4 编译 MiBench 中的 patricia遇到的 rpc 库问题
c语言·c++
hsjkdhs6 小时前
万字详解C++之构造函数析构函数
开发语言·c++
Lin_Aries_04216 小时前
容器化简单的 Java 应用程序
java·linux·运维·开发语言·docker·容器·rpc
techdashen7 小时前
12分钟讲解Python核心理念
开发语言·python
闭着眼睛学算法7 小时前
【华为OD机考正在更新】2025年双机位A卷真题【完全原创题解 | 详细考点分类 | 不断更新题目 | 六种主流语言Py+Java+Cpp+C+Js+Go】
java·c语言·javascript·c++·python·算法·华为od
山海不说话7 小时前
Java后端面经(八股——Redis)
java·开发语言·redis
郝学胜-神的一滴7 小时前
谨慎地迭代函数所收到的参数 (Effective Python 第31条)
开发语言·python·程序人生·软件工程