0_0_36449078_15787.cpp:30:1: error: 'unordered_map' does not name a type unordered_map <int, int> a; ^ 0_0_36449078_15787.cpp: In function 'int main()': 0_0_36449078_15787.cpp:57:9: error: 'a' was not declared in this scope a.clear(); ^