Custom definition of std::hash

Round H 2021 - Kick Start 2021 Silly Substitutions (Vamsi's submission)

template<> struct std::hash<std::list<int>::iterator> {
    size_t operator()(list<int>::iterator const& it) const noexcept {
        return hash<int*>()(&*it); // assuming that iterators contain data at different addresses
    }
};

void solve() {
    int n; string s; cin >> n >> s;
    list<int> l; for (auto const& c : s) l.push_back(c - '0');
    unordered_set<list<int>::iterator> p[10];
    // ... ... ...