4.26 腾讯实习生测试题

import java.util.*; class Queue1{ int data[]=new int[50]; int front=0; int rear=0; public  void PUSH(int x){ this.data[rear]=x; rear=rear+1;
    } public  int SIZE(){ return rear-front;
    } public void POP(){ if(this.SIZE()!=0){ this.front+=1;
        } else  System.out.println(-1);
    } public int TOP(){ if(this.SIZE()!=0) return this.data[front]; else  return -1;
    } public void CLEAR(){ this.front=this.rear=0;
    }
} public class Main{ public static void main(String[] args){
        Queue1 q=new Queue1();
        Scanner scr=new Scanner(System.in); int m=Integer.parseInt(scr.next()); for(int j=0;j<m;j++) { int k=Integer.parseInt(scr.next()); for (int i = 0; i < k; i++) {
                String s = scr.next(); if (s.equals("PUSH")) { int t = scr.nextInt();
                    q.PUSH(t);
                } else if (s.equals("POP"))
                    q.POP(); else if (s.equals("TOP"))
                    System.out.println(q.TOP()); else if(s.equals("SIZE"))
                    System.out.println(q.SIZE()); else if(s.equals("CLEAR"))
                    q.CLEAR();
            }
        }
    }
}