PAT1093解题报告

#include <iostream>#include <string>using namespace std;long long P = 0, PA = 0, PAT = 0;int main(){string A;cin>>A;for(int i = 0; i < A.length(); ++i){if(A[i] == 'P'){P++;}else if(A[i] == 'A'){PA += P;}else if(A[i] == 'T'){PAT += PA;}}cout<<PAT % 1000000007<<endl;return 0;}