Eroare de compilare: main.cpp: In function 'int main()': main.cpp:13:2: error: 'unordered_set' was not declared in this scope unordered_set<int> s; ^~~~~~~~~~~~~ main.cpp:13:16: error: expected primary-expression before 'int' unordered_set<int> s; ^~~ main.cpp:18:4: error: 's' was not declared in this scope s.insert(x); ^ main.cpp:20:4: error: 's' was not declared in this scope s.erase(x); ^ main.cpp:22:7: error: 's' was not declared in this scope if(s.find(x)!=s.end()) ^ main.cpp:7:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.in", "r", stdin); ^ main.cpp:8:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.out", "w", stdout); ^ Non zero exit status: 1