2 seconds
256 megabytes
standard input
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?
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.
Print the answer to the problem.
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
2
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
2
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.
没想到用前缀和,弱爆了
10091856 | 2015-03-01 08:23:44 | njczy2010 | D - A and B and Interesting Substrings | GNU C++ | Accepted | 62 ms | 7976 KB |
10090622 | 2015-03-01 04:45:07 | njczy2010 | D - A and B and Interesting Substrings | GNU C++ | Time limit exceeded on test 6 | 2000 ms | 12200 KB |
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<string> #define N 100005
#define M 10005
#define mod 1000000007
//#define p 10000007
#define mod2 1000000000
#define ll long long
#define ull unsigned long long
#define LL long long
#define eps 1e-6
//#define inf 2147483647
#define maxi(a,b) (a)>(b)? (a) : (b)
#define mini(a,b) (a)<(b)? (a) : (b) using namespace std; ll a[];
char s[N];
int l;
ll ans;
map<ll,ll>mp[];
ll sum; void ini()
{
ans=;
int i;
int te;
for(i=;i<;i++){
scanf("%I64d",&a[i]);
}
for(i=;i<;i++){
mp[i].clear();
}
scanf("%s",s);
l=strlen(s);
sum=;
for(i=;i<l;i++){
te=s[i]-'a';
ans+=mp[te][sum];
sum+=a[te];
mp[te][sum]++;
}
} void solve()
{ } void out()
{
printf("%I64d\n",ans);
} int main()
{
//freopen("data.in","r",stdin);
//freopen("data.out","w",stdout);
//scanf("%d",&T);
//for(int ccnt=1;ccnt<=T;ccnt++)
//while(T--)
//scanf("%d%d",&n,&m);
while(scanf("%I64d",&a[])!=EOF)
{
ini();
solve();
out();
}
return ;
}