View Compilation Error

0_0_10727470_21857.cpp:17: error: expected init-declarator before "ceil"
0_0_10727470_21857.cpp:17: error: expected `,' or `;' before "ceil"
0_0_10727470_21857.cpp: In function `int main()':
0_0_10727470_21857.cpp:41: error: `hash_it' undeclared (first use this function)
0_0_10727470_21857.cpp:41: error: (Each undeclared identifier is reported only once for each function it appears in.)