Codeforces Round #297 (Div. 2)B. Pasha and String 前缀和

Codeforces Round #297 (Div. 2)B. Pasha and String

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: xxx  Solved: 2xx

题目连接

http://codeforces.com/contest/525/problem/B

Description

Pasha got a very beautiful string s for his birthday, the string consists of lowercase Latin letters. The letters in the string are numbered from 1 to |s| from left to right, where |s| is the length of the given string.

Pasha didn't like his present very much so he decided to change it. After his birthday Pasha spent m days performing the following transformations on his string — each day he chose integer ai and reversed a piece of string (a segment) from position ai to position |s| - ai + 1. It is guaranteed that ai ≤ |s|.

You face the following task: determine what Pasha's string will look like after m days.

Input

The first line of the input contains Pasha's string s of length from 2 to 2·105 characters, consisting of lowercase Latin letters.

The second line contains a single integer m (1 ≤ m ≤ 105) —  the number of days when Pasha changed his string.

The third line contains m space-separated elements ai (1 ≤ ai; ai ≤ |s|) — the position from which Pasha started transforming the string on the i-th day.

Output

In the first line of the output print what Pasha's string s will look like after m days.

Sample Input

Input
abcdef
1
2
 
Input
vwxyz
2
2 2
 
Input
abcdef
3
1 2 3

Sample Output

Output
aedcbf
Output
vwxyz
Output
fbdcea

HINT

 

 

题意:

给你一个字符串,然后给你一个数字i,然后i到s.size()-i直接的位置全部翻转,然后问你m次操作之后,是什么样子

 

题解:

首先,只有翻转奇数次和翻转偶数次两种情况,我们用一个类似前缀和的操作,就可以处理出这个位置究竟翻转了多少次,然后输出就好啦

 

~\(≧▽≦)/~啦啦啦,这道题完啦

 

代码:

 

//qscqesze

#include <cstdio>

#include <cmath>

#include <cstring>

#include <ctime>

#include <iostream>

#include <algorithm>

#include <set>

#include <vector>

#include <sstream>

#include <queue>

#include <typeinfo>

#include <fstream>

#include <map>

typedef long long ll;

using namespace std;

//freopen("D.in","r",stdin);

//freopen("D.out","w",stdout);

#define sspeed ios_base::sync_with_stdio(0);cin.tie(0)

#define maxn 400010

#define mod 10007

#define eps 1e-9

//const int inf=0x7fffffff;   //无限大

const int inf=0x3f3f3f3f;

/*



*/

//**************************************************************************************

inline ll read()

{

    int x=0,f=1;char ch=getchar();

    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}

    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}

    return x*f;

}

int flag[maxn];

int main()

{

    string s;

    cin>>s;

    int n;

    cin>>n;

    for(int i=0;i<n;i++)

    {

        int x=read();

        flag[x-1]++;

    }

    for(int i=1;i<=s.size()/2;i++)

    {

        flag[i]+=flag[i-1];

    }

    for(int i=0;i<s.size();i++)

    {

        if(i<s.size()/2)

        {

            if(flag[i]%2==0)

                cout<<s[i];

            else

                cout<<s[s.size()-i-1];

        }

        else

        {

            if(flag[s.size()-i-1]%2==0)

                cout<<s[i];

            else

                cout<<s[s.size()-i-1];

        }

    }

}

 

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