Codefources 519D. A and B and Interesting Substrings

发布时间：2020-12-13 20:17:54 所属栏目：PHP教程来源：网络整理

导读：D. A and B and Interesting Substrings time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A and B are preparing themselves for programming contests. After several years of doing spo

A and B are preparing themselves for programming contests.

After several years of doing sports programming and solving many problems that require calculating all sorts of abstract objects,A and B also developed rather peculiar tastes.

A likes lowercase letters of the Latin alphabet. He has assigned to each letter a number that shows how much he likes that letter (he has assigned negative numbers to the letters he dislikes).

B likes substrings. He especially likes the ones that start and end with the same letter (their length must exceed one).

Also,A and B have a string s. Now they are trying to find out how many substrings t of a string s are interesting to B (that is, t starts and ends with the same letter and its length is larger than one),and also the sum of values of all letters (assigned by A), except for the first and the last one is equal to zero.

Naturally,A and B have quickly found the number of substrings t that are interesting to them. Can you do it?

Input

The first line contains 26 integers xa,?xb,?...,?xz (?-?105?≤?xi?≤?105) ― the value assigned to letters a,?b,?c,?z respectively.

The second line contains string s of length between 1 and 105 characters,consisting of Lating lowercase letters― the string for which you need to calculate the answer.

Output

Print the answer to the problem.

Sample test(s)

input
1 1 ⑴ 1 1 1 1 1 1 1 1 1 1 1 1 7 1 1 1 8 1 1 1 1 1 1
xabcab

output
2

input
1 1 ⑴ 1 1 1 1 1 1 1 1 1 1 1 1 7 1 1 1 8 1 1 1 1 1 1
aaa

output
2

Note

In the first sample test strings satisfying the condition above are abca and bcab.

In the second sample test strings satisfying the condition above are two occurences of aa.

/* *********************************************** Author :CKboss Created Time :2015年03月05日星期4 16时32分55秒 File Name :D_.cpp ************************************************ */ #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <string> #include <cmath> #include <cstdlib> #include <vector> #include <queue> #include <set> #include <map> using namespace std; typedef long long int LL; const int maxn=100100; int n; LL val[30],presum[maxn]; char str[maxn]; map<LL,int> G[30]; int main() { //freopen("in.txt","r",stdin); //freopen("out.txt","w",stdout); for(int i=0;i<26;i++) cin>>val[i]; cin>>str; n=strlen(str); for(int i=0;i<n;i++) { if(i==0) presum[0]=val[str[i]-'a']; else presum[i]=presum[i⑴]+val[str[i]-'a']; } LL ans=0; G[str[0]-'a'][val[str[0]-'a']]++; for(int i=1;i<n;i++) { int c=str[i]-'a'; LL pn=presum[i⑴]; LL pr=presum[i]; ans+=G[c][pn]; G[c][pr]++; } cout<<ans<<endl; return 0; }

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!