杭電oj Best Reward

題目連結：​​點我​​​ Problem Description

After an uphill battle, General Li won a great victory. Now the head of state decide to reward him with honor and treasures for his great exploit.

One of these treasures is a necklace made up of 26 different kinds of gemstones, and the length of the necklace is n. (That is to say: n gemstones are stringed together to constitute this necklace, and each of these gemstones belongs to only one of the 26 kinds.)

In accordance with the classical view, a necklace is valuable if and only if it is a palindrome - the necklace looks the same in either direction. However, the necklace we mentioned above may not a palindrome at the beginning. So the head of state decide to cut the necklace into two part, and then give both of them to General Li.

All gemstones of the same kind has the same value (may be positive or negative because of their quality - some kinds are beautiful while some others may looks just like normal stones). A necklace that is palindrom has value equal to the sum of its gemstones’ value. while a necklace that is not palindrom has value zero.

Now the problem is: how to cut the given necklace so that the sum of the two necklaces’s value is greatest. Output this value.

Input

The first line of input is a single integer T (1 ≤ T ≤ 10) - the number of test cases. The description of these test cases follows.

For each test case, the first line is 26 integers: v1, v2, …, v26 (-100 ≤ vi ≤ 100, 1 ≤ i ≤ 26), represent the value of gemstones of each kind.

The second line of each test case is a string made up of charactor ‘a’ to ‘z’. representing the necklace. Different charactor representing different kinds of gemstones, and the value of ‘a’ is v1, the value of ‘b’ is v2, …, and so on. The length of the string is no more than 500000.

Output

Output a single Integer: the maximum value General Li can get from the necklace.

Sample Input

2

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

aba

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

acacac

#include <cstdio>
#include <cstring> 
#include <iostream>
#include <cstdlib>
using namespace std;
const int MAXN=550000;
char str[MAXN<<1];
int p[MAXN<<1];
void Manacher(char s[],int len) //Manacher 模闆 
{
    int l=0;
    str[l++]='$';
    str[l++]='#';
    for(int i=0;i<len;i++)
    {
        str[l++]=s[i];
        str[l++]='#';
    } 
    str[l]=0;
    int mx=0,id=0;
    for(int i=0;i<l;i++)
    {
        p[i]=mx>i? min(p[2*id-i],mx-i):1;
        while(str[i+p[i]] == str[i-p[i]]) p[i]++;
        if(i+p[i] > mx)
        {
            mx = i+p[i];
            id=i;
        } 
    }
}
char s[MAXN];
int sum[MAXN<<1];
int v[30];
void get_sum()//字首和 
{
    int len=strlen(str);
    for(int i=1;i<len;i++)
    {
        sum[i] = sum[i-1];
        if('a'<=str[i] && str[i]<='z')
        sum[i] += v[str[i]-'a'+1];

    }
}

int main()
{
    int T;
    cin>>T;
    while(T--)
    {
        for(int i=1;i<=26;i++) scanf("%d",&v[i]);
        scanf("%s",s);
        int len=strlen(s);
        Manacher(s,len);
        get_sum();
        len=strlen(str);//長度為原字元串的2倍再加上首尾兩個。 
        int ans = 0;
        for(int i=3;i<len-1;i=i+2)
        {
           int a1=0,a2=0;
           if((1+i)/2+p[(2+(i-1))/2]-1 >= i-1)  //檢查前半部分能否構成回文字元串，應用p數組的性質 
           a1 = sum[i]-sum[1];
           if((len+i-1)/2-p[(len+i-1)/2]+1 <= i+1)//同理檢查後半部分能否構成回文字元串 
           a2 = sum[len-2]-sum[i];
           if(ans<a1+a2)
             ans = a1+a2;
        }
         cout<<ans<<endl;
    }
}