Andy's First Dictionary（uva 10815） set用法

参考：https://www.cnblogs.com/yjlblog/p/6947747.html

https://blog.csdn.net/hnust_taoshiqian/article/details/43448793

https://blog.csdn.net/liuke19950717/article/details/49450817

https://blog.csdn.net/fanyun_01/article/details/66967710

#include <iostream>
#include <cstdio>
#include <set>
#include <sstream>
using namespace std;
set<string> ans;
int main()
{
    string s,temp;
//    freopen("总结.txt","r",stdin);
    while (cin>>s)//cin遇空格结束 ~ 
    {
        int i;
        for (i=0;i<s.length();i++)
        {
            if (isalpha(s[i]))
            {
                s[i]=tolower(s[i]);
            }
            else
            {
                s[i]=' ';
            }
        }
        stringstream ss(s);//ss流初始化 
        while (ss>>temp)//同一个cin进来的s可能有多个单词~ 
        {
            ans.insert(temp);
        }
    }
    set<string>::iterator it;
    for (it=ans.begin();it!=ans.end();it++)
    {
        cout<<*it<<endl;
    }
    
    return 0;
 }