oldest.cpp:2:22: error: hash_map.h: No such file or directory oldest.cpp:10: error: expected constructor, destructor, or type conversion before '<' token oldest.cpp:11: error: expected constructor, destructor, or type conversion before '<' token oldest.cpp: In function 'int main()': oldest.cpp:24: error: 'h' was not declared in this scope oldest.cpp:25: error: 'h2' was not declared in this scope oldest.cpp:32: error: 'h2' was not declared in this scope oldest.cpp:35: error: 'h' was not declared in this scope oldest.cpp:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result oldest.cpp:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result oldest.cpp:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result oldest.cpp:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result oldest.cpp:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result