func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(int argc, char** argv) {     ios::sync_with_stdio(false);     cin.tie(NULL);     unordered_map<int, int> idx;     int N, x;     cin >> N;     while (N--) {       cin >> x;       if (x) idx[x] = 1;     }     cout << idx.size() << endl;     return 0;   }   