View Compilation Error

0_0_6413323_3688.cpp:3:24: unordered_set: No such file or directory
0_0_6413323_3688.cpp:7: error: expected init-declarator before '<' token
0_0_6413323_3688.cpp:7: error: expected `,' or `;' before '<' token
0_0_6413323_3688.cpp:9: error: expected `,' or `...' before '&' token
0_0_6413323_3688.cpp:9: error: ISO C++ forbids declaration of `HASHSET' with no type
0_0_6413323_3688.cpp: In function `int test(int)':
0_0_6413323_3688.cpp:11: error: `hset' undeclared (first use this function)
0_0_6413323_3688.cpp:11: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6413323_3688.cpp: In function `int main()':
0_0_6413323_3688.cpp:22: error: `HASHSET' undeclared (first use this function)
0_0_6413323_3688.cpp:22: error: expected `;' before "res"
0_0_6413323_3688.cpp:26: error: `res' undeclared (first use this function)