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DesignCircularQueue.java
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DesignCircularQueue.java
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package com.algorithm.playground.leetcode.problems.lc600.lc622;
/**
* https://leetcode.com/problems/design-circular-queue/description/
*/
public class DesignCircularQueue {
public static MyCircularQueue myCircularQueue(int k) {
return new DesignCircularQueue().create(k);
}
private MyCircularQueue create(int k) {
return new MyCircularQueue(k);
}
/**
* Your MyCircularQueue object will be instantiated and called as such:
* MyCircularQueue obj = new MyCircularQueue(k);
* boolean param_1 = obj.enQueue(value);
* boolean param_2 = obj.deQueue();
* int param_3 = obj.Front();
* int param_4 = obj.Rear();
* boolean param_5 = obj.isEmpty();
* boolean param_6 = obj.isFull();
*/
class MyCircularQueue {
private int[] values;
private int front, tail;
/**
* Initialize your data structure here. Set the size of the queue to be k.
*/
public MyCircularQueue(int k) {
values = new int[k + 1];
}
/**
* Insert an element into the circular queue. Return true if the operation is successful.
*/
public boolean enQueue(int value) {
if (isFull()) {
return false;
}
values[tail] = value;
tail = ++tail % values.length;
return true;
}
/**
* Delete an element from the circular queue. Return true if the operation is successful.
*/
public boolean deQueue() {
if (isEmpty()) {
return false;
}
front = ++front % values.length;
return true;
}
/**
* Get the front item from the queue.
*/
public int Front() {
return isEmpty() ? -1 : values[front];
}
/**
* Get the last item from the queue.
*/
public int Rear() {
if (isEmpty()) {
return -1;
}
int idx = tail == 0 ? values.length - 1 : tail - 1;
return values[idx];
}
/**
* Checks whether the circular queue is empty or not.
*/
public boolean isEmpty() {
return tail == front;
}
/**
* Checks whether the circular queue is full or not.
*/
public boolean isFull() {
return (tail + 1) % values.length == front;
}
}
}