Codeforces Round #226 (Div. 2) B

B. Bear and Strings
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

The bear has a string s?=?s1s2... s|s| (record |s| is the string‘s length), consisting of lowercase English letters. The bear wants to count the number of such pairs of indices i,?j (1?≤?i?≤?j?≤?|s|), that string x(i,?j)?=?sisi?+?1... sj contains at least one string "bear" as a substring.

String x(i,?j) contains string "bear", if there is such index k (i?≤?k?≤?j?-?3), that sk?=?bsk?+?1?=?esk?+?2?=?ask?+?3?=?r.

Help the bear cope with the given problem.

Input

The first line contains a non-empty string s (1?≤?|s|?≤?5000). It is guaranteed that the string only consists of lowercase English letters.

Output

Print a single number — the answer to the problem.

Sample test(s)
input
bearbtear
output
6
input
bearaabearc
output
20
Note

In the first sample, the following pairs (i,?j) match: (1,?4),?(1,?5),?(1,?6),?(1,?7),?(1,?8),?(1,?9).

In the second sample, the following pairs (i,?j) match: (1,??4),?(1,??5),?(1,??6),?(1,??7),?(1,??8),?(1,??9),?(1,??10),?(1,??11),?(2,??10),?(2,??11),?(3,??10),?(3,??11),?(4,??10),?(4,??11),?(5,??10),?(5,??11),?(6,??10),?(6,??11),?(7,??10),?(7,??11).

 
Codeforces Round #226 (Div. 2) B
#include <iostream>
#include <string>
#include <stdio.h>
#include <vector>
#include <algorithm>
using namespace std;

int gao(string s){
    vector< pair<int,int> >seg ;
    vector< pair<int,int> >::iterator it ;
    seg.clear() ;
    int i ,Len = s.length() ,L ,R ,ans = 0  ,reL ;
    for(i = 0 ; i <= Len - 4 ; i++){
        if(s[i]==b&&s[i+1]==e&&s[i+2]==a&&s[i+3]==r)
            seg.push_back(make_pair(i+1,i+1+3)) ;
    }
    if(seg.size() == 0)
       return 0 ;
    it = seg.begin() ;
    reL = L = it->first  ;
    R = it->second ;
    ans += L * (Len - R +1) ;
    for(it++; it != seg.end() ; it++){
        L = it->first  ;
        R = it->second ;
        ans += (L - reL) * (Len - R + 1) ;
        reL = L ;
    }
    return ans ;
}

int main(){
    string s ;
    while(cin>>s){
        cout<<gao(s)<<endl ;
    }
    return 0 ;
}
Codeforces Round #226 (Div. 2) B

 

Codeforces Round #226 (Div. 2) B

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