include<bits/stdc++.h> using namespace std;bool is_character(char c) {//判断是否为字符 if((c >= 'a' && c <= 'z') || (c >= 'A' && c<= 'Z') || (c >= '0' && c<= '9')) return true; else return false;}int main() { string s1,s2; while(cin>>...