View Compilation Error

0_0_11201393_19754.cpp: In function `void init()':
0_0_11201393_19754.cpp:16: error: `d' undeclared (first use this function)
0_0_11201393_19754.cpp:16: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11201393_19754.cpp:17: error: `f' undeclared (first use this function)
0_0_11201393_19754.cpp: In function `int main()':
0_0_11201393_19754.cpp:88: error: `f' undeclared (first use this function)
0_0_11201393_19754.cpp:88: error: `d' undeclared (first use this function)