7-1.cpp

Accelerated C++ 课后练习题 本人自己完成、可供参考

#include<iostream>
#include<string>
#include<vector>
#include<map>
using namespace std;

int main()
{
	string s;
	map<string, int> counters;			//store each word and associated counter
	map<int, vector<string> > stat;
	//read the input ,keeping of each word and how often we see it
	while(cin>>s)
	{
		if(s=="exit")
			break;
		++counters[s];
	}

	//write the words and associated counts
	for(map<string, int>::const_iterator it=counters.begin();it!=counters.end();++it)
	{								
		cout<<it->first<<"\t"<<it->second<<endl;
		stat[it->second].push_back(it->first);
	}

	for(map<int, vector<string> >::const_iterator i=stat.begin();i!=stat.end();++i)
	{
		cout<<i->first<<string(5,' ');
	
		for(vector<string>::const_iterator j=i->second.begin();j!=i->second.end();++j)
			cout<<*j<<string(3,' ');
	
	  cout<<endl;
	}

	return 0;
}