1040_有几个PAT

#include<iostream>
#include<string>
#include<algorithm>

using namespace std;
const int N=1000000007;

int main()
{
	string str;
	int result;
	int cntP,cntT;
	while(cin>>str)
	{
		result=0;
		cntP=0;
		cntT=count(str.begin(),str.end(),'T');
		for(int i=0;i<str.length();i++)
		{
			if(str[i]=='A')
			{
				result+=cntT*cntP;
				if(result>N)
					result%=N;
			}
			else if(str[i]=='T')
				--cntT;
			else if(str[i]=='P')
				++cntP;
		}
		cout<<result<<endl;
	}
	return 0;
}