深入了解C++中map用法

/************************************************************************
*
* Map的特点: 1、存储Key-value对
* 2、支持快速查找，查找的复杂度基本是Log(N)
* 3、快速插入，快速删除，快速修改记
*
/************************************************************************/
#include <iostream>
#include <string>
#include <map> 
using namespace std;


int main()
{
 map<const char*,int> m;
 m["a"]=1;
 m["b"]=6;
 m["c"]=9;
 map<const char*,int>::iterator it;
 it=m.begin();
 const char* c =it->first;
 cout<<"first element is :"<<c<<endl;
 int i = m["c"];
 while(it!=m.end()){
 cout << it->first<<";"<<it->second<<endl;
 ++it;
 }
 cout <<"m[\"c\"]="<<i<<endl;
 cout <<"sizeof m:"<<m.size()<<endl;
 cout <<"erase m[\"c\"](1:succ 0:failed):"<<m.erase("c")<<endl;
 cout <<"erase m[\"c\"]:"<<m.erase("c")<<endl;
 cout <<"sizeof m:"<<m.size()<<endl;
 cout<<"m[c]="<<m["c"]<<endl;
 cout<<"sizeof m :"<<m.size()<<endl;

 return 0;

}