View Compilation Error

0_0_8189398_8490.cpp: In function `void tarjan_scc(int)':
0_0_8189398_8490.cpp:24: error: `stack' undeclared (first use this function)
0_0_8189398_8490.cpp:24: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8189398_8490.cpp: In function `int main()':
0_0_8189398_8490.cpp:60: error: expected primary-expression before ')' token