MyQueue.kt

package io.dahgan

/**
 * Queue is a data structure that stores some elements and these elements can be received in FIFO order.
 * That means the first element that is inserted to queue would be the first one that can be removed.
 *
 * Our queue has a limited capacity and can NOT store element more than its capacity.
 *
 * Note to developer:
 *     - define an array of integers to keep the queue elements.
 *     - you can initialize the array with (0) in the beginning
 *     - define a variable "head" to keep the index of first element that has been inserted to queue
 *     - define a variable "tail" to shows that index of free position to insert the new element.
 */
class MyQueue(capacity: Int) {

    /**
     * Inserts the given number to the queue
     * @return true if the insert was successful, false if the queue was full
     */
    fun insert(n: Int): Boolean = false

    /**
     * Removes the first element in the queue and returns it.
     * @return the first element in the queue, -1 if the queue is empty
     */
    fun remove(): Int = -1

    /**
     * Returns the first element in the queue WITHOUT removing it.
     * @return the first element in the queue, -1 if the queue is empty
     */
    fun peek(): Int = -1

    /**
     * Checks if the queue is empty.
     * @return true if the queue is empty, false otherwise
     */
    fun isEmpty(): Boolean = false

    /**
     * Checks if the queue capacity is full.
     * @return true if the queue is full, false otherwise
     */
    fun isFull(): Boolean = false
}