linux下练习 c++ 关联式容器map特性

/*

map.cpp

map特性
不允许key重复
key/value对
key可以当下标访问value,key不存在则插入新的key/value对，以0初始化
*/
#include<iostream>
#include<string>
#include "print.h"
#include<map>
using namespace std;
typedef pair<int,string>  pairmp;
#include<map>
int main()
{
	map<int,string> mp;
	mp.insert(pair<int,string>(1,"aaa"));
	mp.insert(make_pair(5,"bbb"));//自动匹配类型,构造pair
	mp.insert(map<int,string>::value_type(4,"fff"));//内部类型，也能自动构造相应的pair
	mp.insert(make_pair(2,"hhh"));
	mp.insert(make_pair(2,"hhh"));
	mp[2]="hhh1";//有则修改
	mp[3]="ddd";//无则插入
	print(mp.begin(),mp.end());
	return 0;
}

print.h

//print.h

#include <iostream>

using namespace std;

#ifndef print_fun

#define print_fun

template<typename T>

///显示序列数据

void print(T b,T e,char c=' ')

{

	bool isExit=false;

	while (b!=e)

	{

		cout<<*b++<<c;

		isExit=true;

	}

	if(isExit) cout<<endl;

}
template<typename K,typename V>
ostream& operator<<(ostream& o,const pair<K,V>& p)//重载输出map类型元素
{
	return o<<p.first<<':'<<p.second;
}

#endif

#include<iostream>
using namespace std;
#include<fstream>
#include<map>
#include<cstring>
class Candidate{
public:
	Candidate(const string& name=""):m_name(name),m_votes(0){}
	Candidate(const char* name):m_name(name),m_votes(0){}
	const string& name() const{
		return m_name;
	}
	const int& votes() const{
		return m_votes;
	}
	void vote(){
		++ m_votes;
	}
private:
	string m_name;
	int m_votes;
};
//测试投票
void test1(){
	map<char,Candidate> mcc;
	mcc.insert(make_pair('a',Candidate("zhangsan")));
	mcc.insert(pair<char,Candidate>('f',"zhaoyun"));
	mcc['b']=Candidate("lisi");
	typedef map<char,Candidate>::iterator IT;
	typedef map<char,Candidate>::const_iterator CIT;
	for(int i=0;i<5;i++)
	{
		for(CIT it=mcc.begin();it!=mcc.end();it++)
		{
			//it->second.vote();
			cout<<it->first<<":"<<it->second.name()<<"  ";
		}
		cout<<endl<<"请投票：";
		char key;
		cin>>key;
		IT fit=mcc.find(key);

		if(fit==mcc.end()) continue;

		fit->second.vote();
		cout<<"投了一票给"<<fit->first<<endl;

	}
	CIT win=mcc.begin();
	for(CIT it=mcc.begin();it!=mcc.end();it++){
		cout<<it->second.name()<<":"
				<<it->second.votes()<<endl;
		if(it->second.votes()>win->second.votes()) win=it;
	}
	cout<<"最多票数："<<win->second.name()<<endl;

}
class StrCmp{//让字符串大小写不区分
	public:
		bool operator()(const string& a,const string& b){
			return strcasecmp(a.c_str(),b.c_str())<0;
		}
		bool operator()(const char* a,const char* b){
			return strcasecmp(a,b)<0;
		}
};
//统计每个单词出现的次数
void test2()
{
	ifstream ifs("words.txt");
	map<string,int,StrCmp> msi;
	string word;
	while(ifs>>word) msi[word]++;
	ifs.close();
	typedef map<string,int>::iterator IT;
	cout<<"一共"<<msi.size()<<"个单词"<<endl;
	for(IT it=msi.begin();it!=msi.end();it++)
	{
		cout<<it->first<<":"<<it->second<<"\n";
	}
}
int main()
{
	//test1();
	test2();
	return 0;
}