View Compilation Error

0_0_18272863_12657.cpp: In function 'void stack_push(int)':
0_0_18272863_12657.cpp:11:31: error: 'queue' was not declared in this scope
 inline void stack_push(int x){queue[++top]=x;}
                               ^
0_0_18272863_12657.cpp: In function 'int stack_pop()':
0_0_18272863_12657.cpp:12:31: error: 'queue' was not declared in this scope
 inline int stack_pop(){return queue[top--];}
                               ^
0_0_18272863_12657.cpp: In function 'bool spfa()':
0_0_18272863_12657.cpp:24:10: error: 'under' was not declared in this scope
  top=-1; under=0; stack_push(s);
          ^