View Compilation Error

0_0_34204770_31113.cpp: In function 'int main()':
0_0_34204770_31113.cpp:158:13: error: 'q' was not declared in this scope
             q.init(m,n);
             ^
0_0_34204770_31113.cpp:170:34: error: 'mod' was not declared in this scope
             if(q.dance(0)) r=mid-mod;
                                  ^
0_0_34204770_31113.cpp:171:24: error: 'mod' was not declared in this scope
             else l=mid+mod;
                        ^