894. Implement queue using Linkedlist
Implement a First-In-First-Out (FIFO) queue using a singly linked list. The implemented queue should support the following operations: push, pop, peek, and isEmpty.
Implement the LinkedListQueue class:
void push(int x): Adds element x to the end of the queue.
int pop(): Removes and returns the front element of the queue.
int peek(): Returns the front element of the queue without removing it.
boolean isEmpty(): Returns true if the queue is empty, false otherwise.
Example 1:
Input:
["LinkedListQueue", "push", "push", "peek", "pop", "isEmpty"]
[[], [3], [7], [], [], []]
Output:[null, null, null, 3, 3, false]
Explanation:
LinkedListQueue queue = new LinkedListQueue();
queue.push(3);
queue.push(7);
queue.peek(); // returns 3
queue.pop(); // returns 3
queue.isEmpty(); // returns false
Example 2:
Input:
["LinkedListQueue", "push", "pop", "isEmpty"]
[[], [2], [], []]
Output: [null, null, 2, true]
Explanation:
LinkedListQueue queue = new LinkedListQueue();
queue.push(2);
queue.pop(); // returns 2
queue.isEmpty(); // returns true
Now Your Turn!
Pick the correct output for the given inputInput:["LinkedListQueue", "isEmpty"]
[[]]
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Constraints:
- 1 <= numbers of calls made <= 100
- 1 <= x <= 100