View Compilation Error

0_0_4436518_2690.cpp: In function `void init()':
0_0_4436518_2690.cpp:22: error: `fac' undeclared (first use this function)
0_0_4436518_2690.cpp:22: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4436518_2690.cpp:44: error: `k' undeclared (first use this function)
0_0_4436518_2690.cpp: In function `int main()':
0_0_4436518_2690.cpp:89: error: `num' undeclared (first use this function)