View Compilation Error

0_0_13063414_4536.cpp:10:1: error: 'hash_map' does not name a type
 hash_map<long long,int>mp;
 ^
0_0_13063414_4536.cpp: In function 'int main()':
0_0_13063414_4536.cpp:21:3: error: 'mp' was not declared in this scope
   mp.clear();
   ^