You are given string s. Your task is to determine if the given string s contains two non-overlapping substrings "AB" and "BA" (the substrings can go in any order).
The only line of input contains a string s of length between 1 and 105 consisting of uppercase Latin letters.
Print "YES" (without the quotes), if string s contains two non-overlapping substrings "AB" and "BA", and "NO" otherwise.
ABA
NO
BACFAB
YES
AXBYBXA
NO
In the first sample test, despite the fact that there are substrings "AB" and "BA", their occurrences overlap, so the answer is "NO".
In the second sample test there are the following occurrences of the substrings: BACFAB.
In the third sample test there is no substring "AB" nor substring "BA".
拿一个简单题来当做我的第一篇博客吧,就这样,代码都是自己写的,所有有的可能不是最佳的(๑•̀ㅂ•́)و✧
#include <bits/stdc++.h>
using namespace std;
int main()
{
string a;
int len,p,q,k;
while(cin>>a)
{
len=a.size();
k=p=q=0;
for(int i=0;i<len;i++)
{
if(a[i]=='A')
{
if(i+2<len&&a[i+1]=='B'&&a[i+2]=='A')
{
k++;
i+=2;
}
else if(i+1<len&&a[i+1]=='B')
{
p=1;
i++;
}
}
if(a[i]=='B')
{
if(i+2<len&&a[i+1]=='A'&&a[i+2]=='B')
{
k++;
i+=2;
}
else if(i+1<len&&a[i+1]=='A')
{
q=1;
i++;
}
}
}
if(p+q+k>=2)
cout<<"YES"<<endl;
else
cout<<"NO"<<endl;
}
return 0;
}