return NULL) q-rear->next->next if(q==rear) rearrear->next rear->next-rear else rear->next->nextq->next *x=q->data delete q return(rear) 8.设计一个算法判别一个算术表达式的圆括号是否正确配对 Int process( init stack(s) cin>>c while(cl=@) push stack(s, c) if (empty stack(s)) pop stack(s, &a) else return (-1) cin>>c if(empty_ stack(s) return else return (-1)return(NULL); q=rear->next->next; if (q==rear) { rear=rear->next; rear->next=rear; } else { rear->next->next=q->next; } *x=q->data; delete q; return(rear); } ⒏设计一个算法判别一个算术表达式的圆括号是否正确配对。 int process( ) { init_stack(s); cin>>c; while (c!='@') { if (c=='(') push_stack(s,c); if (c==')') { if (!empty_stack(s)) pop_stack(s,&a); else return(-1); } cin>>c; } if (empty_stack(s)) return(1); else return(-1);