Maps are a part of the C++ STL.Maps are associative containers that store elements formed by a combination of a key value and a mapped value, following a specific order.The mainly used member functions of maps are:

• Map Template:

  std::map <key_type, data_type>
  

• Declaration:

  map<string,int>m; //Creates a map m where key_type is of type string and data_type is of type int.
  

• Size:

  int length=m.size(); //Gives the size of the map.
  

• Insert:

  m.insert(make_pair("hello",9)); //Here the pair is inserted into the map where the key is "hello" and the value associated with it is 9.
  

• Erasing an element:

  m.erase(val); //Erases the pair from the map where the key_type is val.
  

• Finding an element:

  map<string,int>::iterator itr=m.find(val); //Gives the iterator to the element val if it is found otherwise returns m.end() .
  Ex: map<string,int>::iterator itr=m.find("Maps"); //If Maps is not present as the key value then itr==m.end().
  

• Accessing the value stored in the key:

  To get the value stored of the key "MAPS" we can do m["MAPS"] or we can get the iterator using the find function and then by itr->second we can access the value.
  

To know more about maps click Here.

You are appointed as the assistant to a teacher in a school and she is correcting the answer sheets of the students.Each student can have multiple answer sheets.So the teacher has queries:

:Add the marks to the student whose name is .

: Erase the marks of the students whose name is .

: Print the marks of the students whose name is . (If didn't get any marks print .)