Pasha and String
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 2·ai ≤ |s|.
You face the following task: determine what Pasha's string will look like after mdays.
Input
The first line of the input contains Pasha's string s of length from 2 to 2·105characters, 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; 2·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 mdays.
Examples
abcdef
1
2
aedcbf
vwxyz
2
2 2
vwxyz
abcdef
3
1 2 3
fbdcea sol:题意:给出一个字符串,读入ai,表示翻转区间[ai,n-ai+1]
Ps:写splay的大佬可以直接去码splay,不用看下面的XJB做法
易知:每个位置翻转两次就相当于没变,于是处理出每个位置翻转的次数,差分就可以了,然后从1~n/2扫一遍,对于操作次数是奇数的位置与对应的位置交换
#include <bits/stdc++.h>
using namespace std;
typedef int ll;
inline ll read()
{
ll s=;
bool f=;
char ch=' ';
while(!isdigit(ch))
{
f|=(ch=='-'); ch=getchar();
}
while(isdigit(ch))
{
s=(s<<)+(s<<)+(ch^); ch=getchar();
}
return (f)?(-s):(s);
}
#define R(x) x=read()
inline void write(ll x)
{
if(x<)
{
putchar('-'); x=-x;
}
if(x<)
{
putchar(x+''); return;
}
write(x/);
putchar((x%)+'');
return;
}
#define W(x) write(x),putchar(' ')
#define Wl(x) write(x),putchar('\n')
const int N=;
int n,Q;
char S[N];
int Sum[N];
int main()
{
int i;
scanf("%s",S+); n=strlen(S+);
R(Q);
for(i=;i<=Q;i++)
{
int x=read();
Sum[x]++;
Sum[n-x+]--;
}
for(i=;i<=n;i++)
{
Sum[i]+=Sum[i-];
}
for(i=;i<=(n/);i++) if(Sum[i]&)
{
swap(S[i],S[n-i+]);
}
for(i=;i<=n;i++) putchar(S[i]);
puts("");
return ;
}
/*
input
abcdef
1
2
output
aedcbf input
vwxyz
2
2 2
output
vwxyz input
abcdef
3
1 2 3
output
fbdcea input
keicnqmuqinhsmtudqcilocxkbqgzhbkitmqwttdyoyvcbxincwjryzknubpacsngorexaldfurondbednowemnnlphhboycfavs
2
5 12
output
keiccyobhhphsmtudqcilocxkbqgzhbkitmqwttdyoyvcbxincwjryzknubpacsngorexaldfurondbednowemnnlniqumqnfavs
*/