c++STL（四）关联容器set与map

#include<iostream>#include<algorithm>#include<map>#include<set>#include<utility>#include<string>using namespace std;//在map中传入比较函数 struct cmp{    bool operator ()(string a, string b)    {        if(a.compare(1,a.size()-1,b,1,b.size()-1)<0) return false;        else return true;    }};int main(){    set<string> ss= {"cc","bb","aa","a","h","ww","d","v","b","aaa"};    map<string,int,cmp> a;    string b;    while(cin>>b) if(ss.find(b)!=ss.end()) ++a[b];    for(auto &i:a) cout<<i.first<<" "<<i.second<<endl;//第一种遍历    /*for(auto iter=a.begin();iter!=a.end();iter++)    {        cout<<iter->first<<" "<<iter->second;    }*///第二种遍历    return 0;}