LeetCode 622 Design Circular Queue

Problem Statement

use std::vec::Vec;

struct MyCircularQueue {
    v : Vec<i32>,
    head : usize,
    tail : usize,
    count : usize
}

/**
 * `&self` means the method takes an immutable reference.
 * If you need a mutable reference, change it to `&mut self` instead.
 */
impl MyCircularQueue {

    /** Initialize your data structure here. Set the size of the queue to be k. */
    fn new(k: i32) -> Self {
        let mut vec = Vec::with_capacity(k.clone() as usize);
        vec.resize(k as usize, 0);
        MyCircularQueue {
            v : vec,
            head : 0, tail : 0, count : 0
        }
    }

    /** Insert an element into the circular queue. Return true if the operation is successful. */
    fn en_queue(&mut self, value: i32) -> bool {
        if self.is_full() {
            return false;
        }

        self.v[self.tail.clone()] = value;
        self.tail = (self.tail + 1) % self.v.len();
        self.count += 1;
        return true;
    }

    /** Delete an element from the circular queue. Return true if the operation is successful. */
    fn de_queue(&mut self) -> bool {
        if self.is_empty() {
            return false;
        }
        self.v[self.head.clone()] = 0;
        self.head = (self.head + 1) % self.v.len();
        self.count -= 1;
        return true;
    }

    /** Get the front item from the queue. */
    fn front(&self) -> i32 {
        if self.is_empty() {
            return - 1;
        }
        return self.v[self.head.clone()];
    }

    /** Get the last item from the queue. */
    fn rear(&self) -> i32 {
        if self.is_empty() {
            return -1;
        }
        return self.v[(self.tail - 1 + self.v.len()) % self.v.len()];
    }

    /** Checks whether the circular queue is empty or not. */
    fn is_empty(&self) -> bool {
        return self.count == 0;
    }

    /** Checks whether the circular queue is full or not. */
    fn is_full(&self) -> bool {
        return self.count == self.v.len();
    }
}