Flipping Game CodeForces - 327A(暴力枚举)

2024-04-20 05:08

本文主要是介绍Flipping Game CodeForces - 327A(暴力枚举),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

Iahub got bored, so he invented a game to be played on paper.

He writes n integers a1, a2, …, an. Each of those integers can be either 0 or 1. He’s allowed to do exactly one move: he chooses two indices i and j (1 ≤ i ≤ j ≤ n) and flips all values ak for which their positions are in range [i, j] (that is i ≤ k ≤ j). Flip the value of x means to apply operation x = 1 - x.

The goal of the game is that after exactly one move to obtain the maximum number of ones. Write a program to solve the little game of Iahub.

Input
The first line of the input contains an integer n (1 ≤ n ≤ 100). In the second line of the input there are n integers: a1, a2, …, an. It is guaranteed that each of those n values is either 0 or 1.

Output
Print an integer — the maximal number of 1s that can be obtained after exactly one move.

Examples
Input
5
1 0 0 1 0
Output
4
Input
4
1 0 0 1
Output
4
Note
In the first case, flip the segment from 2 to 5 (i = 2, j = 5). That flip changes the sequence, it becomes: [1 1 1 0 1]. So, it contains four ones. There is no way to make the whole sequence equal to [1 1 1 1 1].

In the second case, flipping only the second and the third element (i = 2, j = 3) will turn all numbers into 1.

题意: 给定一个序列,找出一个子区间,中的1变为0, 0变为1,求最终这个序列中有几个1。

思路 :暴力枚举区间,我做了小改动,将原序列的0变为1, 1变为-1,求区间和的最大值,然后加上区间外和区间内的1的个数。

代码:

#include<stdio.h>
int main()
{int a[10010],b[10010];int n;while(~scanf("%d",&n)){for(int i=0;i<n;i++)scanf("%d",&a[i]);for(int i=0;i<n;i++)if(a[i]==0)b[i]=1;elseb[i]=-1;int p=0,sum=0,max=-4324,z,y;for(int i=p;i<n;i++){sum+=b[i];if(sum>max){max=sum;z=p;y=i;}if(sum<0){sum=0;p=i+1;}}int s=0;for(int i=0;i<z;i++)if(a[i]==1)s++; for(int i=y+1;i<n;i++)if(a[i]==1)s++;int ss=0;for(int i=z;i<=y;i++)if(a[i]==1)ss++;printf("%d\n",s+max+ss); }return 0;
}

这篇关于Flipping Game CodeForces - 327A(暴力枚举)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/919349

相关文章

hdu 2489 (dfs枚举 + prim)

题意: 对于一棵顶点和边都有权值的树,使用下面的等式来计算Ratio 给定一个n 个顶点的完全图及它所有顶点和边的权值,找到一个该图含有m 个顶点的子图,并且让这个子图的Ratio 值在所有m 个顶点的树中最小。 解析: 因为数据量不大,先用dfs枚举搭配出m个子节点,算出点和,然后套个prim算出边和,每次比较大小即可。 dfs没有写好,A的老泪纵横。 错在把index在d

Codeforces Round #240 (Div. 2) E分治算法探究1

Codeforces Round #240 (Div. 2) E  http://codeforces.com/contest/415/problem/E 2^n个数,每次操作将其分成2^q份,对于每一份内部的数进行翻转(逆序),每次操作完后输出操作后新序列的逆序对数。 图一:  划分子问题。 图二: 分而治之,=>  合并 。 图三: 回溯:

Codeforces Round #261 (Div. 2)小记

A  XX注意最后输出满足条件,我也不知道为什么写的这么长。 #define X first#define Y secondvector<pair<int , int> > a ;int can(pair<int , int> c){return -1000 <= c.X && c.X <= 1000&& -1000 <= c.Y && c.Y <= 1000 ;}int m

Codeforces Beta Round #47 C凸包 (最终写法)

题意慢慢看。 typedef long long LL ;int cmp(double x){if(fabs(x) < 1e-8) return 0 ;return x > 0 ? 1 : -1 ;}struct point{double x , y ;point(){}point(double _x , double _y):x(_x) , y(_y){}point op

Codeforces Round #113 (Div. 2) B 判断多边形是否在凸包内

题目点击打开链接 凸多边形A, 多边形B, 判断B是否严格在A内。  注意AB有重点 。  将A,B上的点合在一起求凸包,如果凸包上的点是B的某个点,则B肯定不在A内。 或者说B上的某点在凸包的边上则也说明B不严格在A里面。 这个处理有个巧妙的方法,只需在求凸包的时候, <=  改成< 也就是说凸包一条边上的所有点都重复点都记录在凸包里面了。 另外不能去重点。 int

Codeforces 482B 线段树

求是否存在这样的n个数; m次操作,每次操作就是三个数 l ,r,val          a[l] & a[l+1] &......&a[r] = val 就是区间l---r上的与的值为val 。 也就是意味着区间[L , R] 每个数要执行 | val 操作  最后判断  a[l] & a[l+1] &......&a[r] 是否= val import ja

计蒜客 Half-consecutive Numbers 暴力打表找规律

The numbers 11, 33, 66, 1010, 1515, 2121, 2828, 3636, 4545 and t_i=\frac{1}{2}i(i+1)t​i​​=​2​​1​​i(i+1), are called half-consecutive. For given NN, find the smallest rr which is no smaller than NN

hdu 6198 dfs枚举找规律+矩阵乘法

number number number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description We define a sequence  F : ⋅   F0=0,F1=1 ; ⋅   Fn=Fn

fzu 2275 Game KMP

Problem 2275 Game Time Limit: 1000 mSec    Memory Limit : 262144 KB  Problem Description Alice and Bob is playing a game. Each of them has a number. Alice’s number is A, and Bob’s number i

【Rust练习】12.枚举

练习题来自:https://practice-zh.course.rs/compound-types/enum.html 1 // 修复错误enum Number {Zero,One,Two,}enum Number1 {Zero = 0,One,Two,}// C语言风格的枚举定义enum Number2 {Zero = 0.0,One = 1.0,Two = 2.0,}fn m