How do I loop through a unordered_map in C++ without auto?

I am trying to loop through an unordered_map, to find if any of its VALUES is greater than 2. But this syntax is wrong

unordered_map<int, int> mp;
        
for (int i = 0; i < N; i++)
{
    mp[arr[i]]++;
}

for (int i = 0; i < mp.size(); i++ ) {
    cout << mp[i].second << " " << endl; //mp[i].second is wrong syntax

    if (mp[i].second > 2) {
        cout << "WRONG";
        x = false;
        break;
    }
}

how can I do this?

Solution

It seems that you assumed(incorrectly) that mp[i] is std::pair<int, int> when in fact mp[i] gives you the mapped value which is of type int in your example. This can be seen from std::map::operator[]:

T& operator[]( Key&& key ); (2)
Returns a reference to the value that is mapped to a key equivalent to key, performing an insertion if such key does not already exist.

(emphasis mine)

Method 1

Since you don't want to use auto, you can explicitly write the type std::pair<const int, int> in the range-based for loop as shown below:

//---------vvvvvvvvvvvvvvvvvvvvvvvv--------------------->not using auto here as you want
for (const std::pair<const int, int> &pair_elem: mp) {
    cout << pair_elem.second << " " << endl; 
    if (pair_elem.second > 2) {
        cout << "WRONG";
        //other code here
    }
}

Method 2

Note that you can also use std::find_if instead of a for loop as shown below:

auto iter = std::find_if(mp.begin(), mp.end(), [](const std::pair<int,int>& elem) 
                            { return elem.second > 2;});
   if (iter != mp.end())
       std::cout << "Greater found ";
   else 
   {
       std::cout<<"Greater not found"<<std::endl;
   }

Demo