不是题解

#include<iostream>
#include<string>
std::string strA,strB,strC,str;int main(void){std::cin>>strA;std::cin>>//strB;std::cin>>strC;str = strA + strB;if(str.find(strC)!=-1){std::cout<<strC<<" is substring of "<<strA<<" and "<<strB;}else{std::cout<<strC<<" is not substring of "<<strA<<" and "<<strB;}}