Problem : https://www.hackerrank.com/challenges/cpp-maps/problem
Solution :
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <set>
#include <map>
#include <algorithm>
using namespace std;
int main() {
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
int Q;
cin>>Q;
map<string,int>mp;
while(Q--){
int type;
cin>>type;
if(type == 1){
string name;
int marks;
cin>>name>>marks;
if(mp.find(name)!=mp.end()){
mp[name] = mp[name] + marks;
}else{
mp[name] = marks;
}
}else if(type == 2){
string name;
cin>>name;
mp[name] = 0;
}else if(type == 3){
string name;
cin>>name;
cout<<mp[name]<<endl;
}
}
return 0;
}