Page Faults in LRU (GFG)

class Solution{
public:
    int pageFaults(int N, int C, int pages[]){
        // code here
        int fault = 0;
        list<int> List;
        unordered_map<int, list<int>::iterator> Map;
        for(int i = 0; i < N; i++) {
            if(Map.find(pages[i]) != Map.end()) {
                List.erase(Map[pages[i]]);
                List.push_back(pages[i]);
                auto iter = List.end();
                Map.insert({pages[i], --iter});
            }
            else {
                fault++;
                if(List.size() == C) {
                    Map.erase(List.front());
                    List.pop_front();
                } 
                List.push_back(pages[i]);
                auto iter = List.end();
                Map.insert({pages[i], --iter});
            }
        }
        return fault;
    }
};