题目很简单，只需要注意带空格的输入用getline即可
#include <iostream> #include <vector> #include <algorithm> #include <string> #include <set> using namespace std; int main(){ string str; getline(cin,str); set<char> a; for(int i= 1 ; i < str.length()-1; i+=3 ){ a.insert(str[i]); } cout<<a.size()<<endl; }
Codeforces Round #253 (Div. 2) A. Anton and Letters,布布扣,bubuko.com
Codeforces Round #253 (Div. 2) A. Anton and Letters
原文：http://www.cnblogs.com/xiongqiangcs/p/3799795.html