map
= key , value pair

Unique value only -> Depends on key
Always sorted depends on key

#include 
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
map mp ;
mp.insert({10,20}) ;
mp.insert({2,10}) ;
mp [10] = 20 ;
mp[2] = 12 ;

mp[10] = 100 ;

cout << mp[10] << '\n' ;


// for(auto [key,value] :mp)
// {
//     cout << key << "->" << value << '\n' ;
// }
for(auto it : mp)
{
    int key = it.first , value = it.second ;

    cout << key << "->" << value ;
    cout << '\n' ;
}

auto it = mp.find(10) ;

auto it=mp.find(10) ;
cout << it->second << '\n' ;


}