View Compilation Error

0_0_4537409_3179.cpp: In function `bool check()':
0_0_4537409_3179.cpp:7: error: `n' undeclared (first use this function)
0_0_4537409_3179.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4537409_3179.cpp:10: error: `m' undeclared (first use this function)
0_0_4537409_3179.cpp: In function `int main()':
0_0_4537409_3179.cpp:16: error: `n' undeclared (first use this function)
0_0_4537409_3179.cpp:22: error: `mid' undeclared (first use this function)