Mega Code Archive
0349 ArrayDeque Class
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ArrayDeque class extends AbstractCollection and implements the Deque interface.
ArrayDeque creates a dynamic array and has no capacity restrictions. ArrayDeque is a generic class that has this declaration:
class ArrayDeque<E>
E specifies the type of objects stored in the collection.
ArrayDeque defines the following constructors:
ArrayDeque( )
builds an empty deque. starting capacity is 16.
ArrayDeque(int size)
builds a deque that has the specified initial capacity.
ArrayDeque(Collection<? extends E> c)
creates a deque that is initialized with the elements of the collection passed in c.
The following program demonstrates ArrayDeque by using it to create a stack:
import java.util.ArrayDeque;
public class Main {
public static void main(String args[]) {
ArrayDeque<String> adq = new ArrayDeque<String>();
adq.push("A");
adq.push("B");
adq.push("D");
adq.push("E");
adq.push("F");
while (adq.peek() != null){
System.out.println(adq.pop() + " ");
}
}
}
The following code uses an array deque as a stack
import java.util.ArrayDeque;
import java.util.Deque;
public class Main {
public static void main(String[] args) {
Deque<String> stack = new ArrayDeque<String>();
String[] weekdays = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" };
for (String weekday : weekdays){
stack.push(weekday);
}
while (stack.peek() != null){
System.out.println(stack.pop());
}
}
}
Saturday
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import java.util.ArrayDeque;
import java.util.Deque;
public class Main {
public static void main(String[] args) {
MyDequeue stack = new MyDequeue();
for (int i = 0; i < 5; i++) {
stack.push(i);
}
System.out.println("After pushing 5 elements: " + stack);
int m = stack.pop();
System.out.println("Popped element = " + m);
System.out.println("After popping 1 element : " + stack);
int n = stack.peek();
System.out.println("Peeked element = " + n);
System.out.println("After peeking 1 element : " + stack);
}
}
class MyDequeue {
private Deque<Integer> data = new ArrayDeque<Integer>();
public void push(Integer element) {
data.addFirst(element);
}
public Integer pop() {
return data.removeFirst();
}
public Integer peek() {
return data.peekFirst();
}
public String toString() {
return data.toString();
}
}
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