Codeforces 519D A and B and Interesting Substrings

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 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 -1 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 -1 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.

开一个map【26】,维护相同字母的和,看代码

 

#include <map>
#include <set>
#include <list>
#include <stack>
#include <queue>
#include <cmath>
#include <ctime>
#include <cstdio>
#include <vector>
#include <sstream>
#include <cstdlib>
#include <complex>
#include <cstring>
#include <iostream>
#include <algorithm>

#define REP(i,N) for (int i = 0;i < (N);i++)
#define REP_1(i,N) for (int i = 1;i < (N);i++)
#define REP_2(i,be,en) for (int i = (be);i < (en);i++)
#define DWN(i,N) for (int i = (N);i >= 0;i--)
#define DWN_1(i,N) for (int i = (N);i >= 1;i--)
#define DWN_2(i,en,be) for (int i = (en);i >= (be);i--)
#define FR(N) freopen((N),"r",stdin)
#define FW(N) freopen((N),"w",stdout)
#define GETS(ch) fgets((ch),MAXN,stdin);
#define INF 0x3f3f3f3f
#define MAXN 100010 * 52
using namespace std;

typedef long long LL;
typedef map<LL,LL> MINT;
typedef vector<int> VINT;
typedef set<int> SINT;

int a[26];
MINT m[26];
LL ans = 0;
int main () {
	//FR("1.txt");
	REP(i,26) {
		cin >> a[i];
	}
	string str;
	cin >> str;
	int len = str.length();
	LL cnt = 0;
	REP(i,len) {
		ans += m[str[i] - 'a'][cnt];
		cnt += a[str[i] - 'a'];
		m[str[i] - 'a'][cnt]++;
	}
	cout << ans << endl;
}

  

posted @ 2015-03-01 09:08  闪光阳  阅读(411)  评论(0编辑  收藏  举报