标签：val des double rtl follow ++ return value use
Design your implementation of the circular double-ended queue (deque).
Your implementation should support following operations:
MyCircularDeque(k): Constructor, set the size of the deque to be k.insertFront(): Adds an item at the front of Deque. Return true if the operation is successful.insertLast(): Adds an item at the rear of Deque. Return true if the operation is successful.deleteFront(): Deletes an item from the front of Deque. Return true if the operation is successful.deleteLast(): Deletes an item from the rear of Deque. Return true if the operation is successful.getFront(): Gets the front item from the Deque. If the deque is empty, return -1.getRear(): Gets the last item from Deque. If the deque is empty, return -1.isEmpty(): Checks whether Deque is empty or not. isFull(): Checks whether Deque is full or not.Example:
MyCircularDeque circularDeque = new MycircularDeque(3); // set the size to be 3 circularDeque.insertLast(1); // return true circularDeque.insertLast(2); // return true circularDeque.insertFront(3); // return true circularDeque.insertFront(4); // return false, the queue is full circularDeque.getRear(); // return 2 circularDeque.isFull(); // return true circularDeque.deleteLast(); // return true circularDeque.insertFront(4); // return true circularDeque.getFront(); // return 4
1 class MyCircularDeque { 2 int[] a; 3 int front, rear, cap, size; 4 5 public MyCircularDeque(int k) { 6 a = new int[k]; 7 cap = k; 8 } 9 10 /** Adds an item at the front of Deque. Return true if the operation is successful. */ 11 public boolean insertFront(int value) { 12 if(isFull()) return false; 13 // because we set the initial value of front to be 0 14 if (size != 0) { 15 front = (front - 1 + cap) % cap; 16 } 17 a[front] = value; 18 size++; 19 return true; 20 } 21 22 /** Adds an item at the rear of Deque. Return true if the operation is successful. */ 23 public boolean insertLast(int value) { 24 if(isFull()) return false; 25 // because we set the initial value of rear to be 0 26 if (size != 0) { 27 rear = (rear + 1) % cap; 28 } 29 a[rear] = value; 30 size++; 31 return true; 32 } 33 34 /** Deletes an item from the front of Deque. Return true if the operation is successful. */ 35 public boolean deleteFront() { 36 if(isEmpty()) return false; 37 size--; 38 if (size != 0) { 39 front = (front + 1) % cap; 40 } 41 return true; 42 } 43 44 /** Deletes an item from the rear of Deque. Return true if the operation is successful. */ 45 public boolean deleteLast() { 46 if(isEmpty()) return false; 47 size--; 48 if (size != 0) { 49 rear = (rear - 1 + cap) % cap; 50 } 51 return true; 52 } 53 54 /** Get the front item from the deque. */ 55 public int getFront() { 56 return isEmpty() ? -1 : a[front]; 57 } 58 59 /** Get the last item from the deque. */ 60 public int getRear() { 61 return isEmpty() ? -1 : a[rear]; 62 } 63 64 /** Checks whether the circular deque is empty or not. */ 65 public boolean isEmpty() { 66 return size == 0; 67 } 68 69 /** Checks whether the circular deque is full or not. */ 70 public boolean isFull() { 71 return size == cap; 72 } 73 }
标签：val des double rtl follow ++ return value use
原文地址：https://www.cnblogs.com/beiyeqingteng/p/11333975.html
