hello-algo/en/codes/dart/chapter_stack_and_queue/deque.dart

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1.2 KiB
Dart

/**
* File: deque.dart
* Created Time: 2023-03-28
* Author: liuyuxin (gvenusleo@gmail.com)
*/
import 'dart:collection';
void main() {
/* Initialize double-ended queue */
final Queue<int> deque = Queue();
deque.addFirst(3);
deque.addLast(2);
deque.addLast(5);
print("Double-ended queue deque = $deque");
/* Access element */
final int peekFirst = deque.first;
print("Front element peekFirst = $peekFirst");
final int peekLast = deque.last;
print("Back element peekLast = $peekLast");
/* Element enqueue */
deque.addLast(4);
print("Element 4 enqueued at the back, deque = $deque");
deque.addFirst(1);
print("Element 1 enqueued at the front, deque = $deque");
/* Element dequeue */
final int popLast = deque.removeLast();
print("Back dequeue element = $popLast, deque after back dequeue = $deque");
final int popFirst = deque.removeFirst();
print("Front dequeue element = $popFirst, deque after front dequeue = $deque");
/* Get the length of the double-ended queue */
final int size = deque.length;
print("Double-ended queue length size = $size");
/* Determine if the double-ended queue is empty */
final bool isEmpty = deque.isEmpty;
print("Is the double-ended queue empty = $isEmpty");
}