AcWing 828. 模拟栈 -- Jvav
原题链接
简单
作者:
domiso
,
2021-08-26 18:28:09
,
所有人可见
,
阅读 226
import java.util.*;
public class Main{
final static int N = 100010;
static int[] stk = new int[N];
static int tt = -1;
public static void push(int x){
stk[++tt] = x;
}
public static int pop(){
return stk[tt--];
}
public static int query(){
return stk[tt];
}
public static boolean empty(){
return tt == -1;
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int m = sc.nextInt();
while(m-- >= 0) {
String[] s = sc.nextLine().split(" ");
if(s[0].equals("push")){
push(Integer.parseInt(s[1]));
}
else if(s[0].equals("pop")){
pop();
}
else if(s[0].equals("query")) {
System.out.println(query());
}
else if(s[0].equals("empty")) {
if(empty()) System.out.println("YES");
else System.out.println("NO");
}
}
}
}