Java ArrayDeque contains()方法

Java中的Java.util.ArrayDeque.contains()方法用于检查或验证Deque中是否存在特定元素。

语法

Array_Deque.contains(Object element)

参数： 参数element是ArrayDeque的类型。

返回值： 如果元素存在于deque中，该方法返回True，否则返回False。

contains()方法的 时间复杂度 是 O(N)，即线性

以下程序说明了Java.util.ArrayDeque.contains()方法。

程序1 :

// Java code to illustrate contains()
import java.util.*;
   
public class ArrayDequeDemo {
    public static void main(String args[])
    {
        // Creating an empty ArrayDeque
        Deque<String> de_que = new ArrayDeque<String>();
   
        // Use add() method to add elements into the Queue
        de_que.add("Welcome");
        de_que.add("To");
        de_que.add("Geeks");
        de_que.add("4");
        de_que.add("Geeks");
   
        // Displaying the ArrayDeque
        System.out.println("ArrayDeque: " + de_que);
   
        // Check for "Geeks" in the deque
        System.out.println("Does the deque contains 'Geeks'? "
                           + de_que.contains("Geeks"));
   
        // Check for "4" in the deque
        System.out.println("Does the deque contains '4'? "
                           + de_que.contains("4"));
   
        // Check if the deque contains "No"
        System.out.println("Does the deque contains 'No'? "
                           + de_que.contains("No"));
    }
}

输出

ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
Does the deque contains 'Geeks'? true
Does the deque contains '4'? true
Does the deque contains 'No'? false

程序2 :

// Java code to illustrate contains()
import java.util.*;
   
public class ArrayDequeDemo {
    public static void main(String args[])
    {
        // Creating an empty ArrayDeque
        Deque<Integer> de_que = new ArrayDeque<Integer>();
   
        // Use add() method to add elements into the Queue
        de_que.add(10);
        de_que.add(15);
        de_que.add(30);
        de_que.add(20);
        de_que.add(5);
   
        // Displaying the ArrayDeque
        System.out.println("ArrayDeque: " + de_que);
   
        // Check for '15' in the Deque
        System.out.println("Does the Deque contains '15'? "
                           + de_que.contains(15));
   
        // Check for '2' in the Deque
        System.out.println("Does the Deque contains '2'? "
                           + de_que.contains(2));
   
        // Check if the Deque contains '10'
        System.out.println("Does the Deque contains '10'? "
                           + de_que.contains(10));
    }
}

输出

ArrayDeque: [10, 15, 30, 20, 5]
Does the Deque contains '15'? true
Does the Deque contains '2'? false
Does the Deque contains '10'? true