View Compilation Error

0_0_39174974_31931.cpp: In function 'int main()':
0_0_39174974_31931.cpp:17:29: error: 'q' was not declared in this scope
   17 |                         if(!q.empty()&&z[i]==q.top()){
      |                             ^
0_0_39174974_31931.cpp:41:29: error: 'q' was not declared in this scope
   41 |                         if(!q.empty()&&z[i]==q.top())i++,q.pop();
      |                             ^
0_0_39174974_31931.cpp:50:29: error: 'q' was not declared in this scope
   50 |                         if(!q.empty()&&z[i]==q.top())i++,q.pop();
      |                             ^