## Algorithm

Problem Name: Maps-STL

In this HackerRank Functions in C++ programming problem solution,

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.


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 Q queries:

1 X Y :Add the marks Y to the student whose name is X.

2 X: Erase the marks of the students whose name is X.

3 X: Print the marks of the students whose name is X. (If X didn't get any marks print 0.)

Input Format

The first line of the input contains Q where Q is the number of queries. The next Q lines contain 1 query each.The first integer, type f each query is the type of the query.If query is of type 1, it consists of one string and an integer X and y where X is the name of the student and Y is the marks of the student.If query is of type 2 or 3 ,it consists of a single string X where X s the name of the student.

Constraints

1 <= Q <= 10**5

1 <= type <= 3

1 <= |X|<= 6

1 <= Y <= 10**3

Output Format

For queries of type 3 print the marks of the given student.

Sample Input

7
1 Jesse 20
1 Jess 12
1 Jess 18
3 Jess
3 Jesse
2 Jess
3 Jess


Sample Output

30
20
0


## Code Examples

### #1 Code Example with C++ Programming

Code - C++ Programming


#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <set>
#include <map>
#include <algorithm>
using namespace std;

int main()
{
int T;
cin >> T;

string s;
map m;
map::iterator it;

for(int i = 1, t; i <= T; i++){
cin >> t >> s;
int val;
switch(t)
{
case 1:
cin >> val;
m[s] += val;
break;
case 2:
m.erase(s);
break;
case 3:
it = m.find(s);
cout << (it != m.end() ? ((*it).second) : 0) << endl;
}
}

return 0;
}

Copy The Code &

Input

cmd
7 1 Jesse 20 1 Jess 12 1 Jess 18 3 Jess 3 Jesse 2 Jess 3 Jess

Output

cmd
30 20 0