View Compilation Error

0_0_2016851_29338.cpp: In function `int nn(int*)':
0_0_2016851_29338.cpp:39: error: `cf' undeclared (first use this function)
0_0_2016851_29338.cpp:39: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2016851_29338.cpp: In function `void cf(int*, int*)':
0_0_2016851_29338.cpp:51: error: `void cf(int*, int*)' used prior to declaration