View Compilation Error

354829_0_25452.cpp:6:20: hash_set: No such file or directory
354829_0_25452.cpp: In function `int main()':
354829_0_25452.cpp:79: error: `hash_set' undeclared (first use this function)
354829_0_25452.cpp:79: error: (Each undeclared identifier is reported only once for each function it appears in.)
354829_0_25452.cpp:79: error: expected primary-expression before '>' token
354829_0_25452.cpp:79: error: `visited' undeclared (first use this function)