STL——map

 1 #include <map>
 2 #include <iostream>
 3 using namespace std;
 4 int main( )
 5 {
 6 map <int, int> m1, m2, m3;
 7 map <int, int>::iterator m1_Iter;
 8 
 9 m1.insert ( pair <int, int> ( 1, 10 ) );
10 m1.insert ( pair <int, int> ( 2, 20 ) );
11 m1.insert ( pair <int, int> ( 3, 30 ) );
12 
13 m2.insert ( pair <int, int> ( 10, 100 ) );
14 m2.insert ( pair <int, int> ( 20, 200 ) );
15 
16 m3.insert ( pair <int, int> ( 30, 300 ) );
17 
18 cout << "The original map m1 is:";
19 for ( m1_Iter = m1.begin( ); m1_Iter != m1.end( ); m1_Iter++ )
20 cout << " " << m1_Iter->second;
21 cout << "." << endl;
22 // This is the member function version of swap
23 //m2 is said to be the argument map; m1 the target map
24 
25 m1.swap( m2 );
26 cout << "After swapping with m2, map m1 is:";
27 for ( m1_Iter = m1.begin( ); m1_Iter != m1.end( ); m1_Iter++ )
28 cout << " " << m1_Iter -> second;
29 cout << "." << endl;
30 
31 cout << "After swapping with m2, map m2 is:";
32 for ( m1_Iter = m2.begin( ); m1_Iter != m2.end( ); m1_Iter++ )
33 cout << " " << m1_Iter -> second;
34 cout << "." << endl;
35 
36 // This is the specialized template version of swap
37 swap( m1, m3 );
38 cout << "After swapping with m3, map m1 is:";
39 for ( m1_Iter = m1.begin( ); m1_Iter != m1.end( ); m1_Iter++ )
40 cout << " " << m1_Iter -> second;
41 cout << "." << endl;
42 }

 1 #include <iostream>
 2 
 3 #include <map>
 4 
 5 using namespace std;
 6 
 7 int main(void)
 8 
 9 {
10 
11 map<char,int,less<char> > map1;
12 
13 map<char,int,less<char> >::iterator mapIter;
14 
15 //char 是键的类型，int是值的类型
16 
17 //下面是初始化，与数组类似
18 
19 //也可以用map1.insert(map<char,int,less<char> >::value_type(‘c‘,3));
20 
21 map1[‘c‘]=3;
22 
23 map1[‘d‘]=4;
24 
25 map1[‘a‘]=1;
26 
27 map1[‘b‘]=2;
28 
29 for(mapIter=map1.begin();mapIter!=map1.end();++mapIter)
30 
31 cout<<" "<<(*mapIter).first<<": "<<(*mapIter).second;
32 
33 //first对应定义中的char键，second对应定义中的int值
34 
35 //检索对应于d键的值是这样做的：
36 
37 map<char,int,less<char> >::const_iterator ptr;
38 
39 ptr=map1.find(‘d‘);
40 
41 cout<<‘‘\n‘‘<<" "<<(*ptr).first<<" 键对应于值："<<(*ptr).second;
42 
43 cin.get();
44 
45 return 0;
46 
47 }
48 
49 //从以上例程中，我们可以看到map对象的行为和一般数组的行为类似。Map允许两个或多个值使用比较操作符。

#include <iostream>

#include <map>

#include <string>

using namespace std;

int main(void)

{

multimap<string,string,less<string> >mulmap;

multimap<string,string,less<string> >::iterator p;

//初始化多重映射mulmap:

typedef multimap<string,string,less<string> >::value_type vt;

typedef string s;

mulmap.insert(vt(s("Tom "),s("is a student")));

mulmap.insert(vt(s("Tom "),s("is a boy")));

mulmap.insert(vt(s("Tom "),s("is a bad boy of blue!")));

mulmap.insert(vt(s("Jerry "),s("is a student")));

mulmap.insert(vt(s("Jerry "),s("is a beatutiful girl")));

mulmap.insert(vt(s("DJ "),s("is a student")));

//输出初始化以后的多重映射mulmap:

for(p=mulmap.begin();p!=mulmap.end();++p)

cout<<(*p).first<<(*p).second<<endl;

//检索并输出Jerry键所对应的所有的值

cout<<"find Jerry :"<<endl;

p=mulmap.find(s("Jerry "));

while((*p).first=="Jerry ")

{

cout<<(*p).first<<(*p).second<<endl;

++p;

}

cin.get();

return 0;

}

//在map中是不允许一个键对应多个值的，在multimap中，不支持operator[],也就是说不支持map中允许的下标操作。