Implement Queue using Arrays
Difficulty: Basic
Acceptance: %
Points: 10.00
Implement a Queue using an array to handle the following types of queries:
- Push operation (1 x): This query adds the element x to the queue.
- Pop operation (2): This query removes and returns the front element from the queue. If the queue is empty, return -1.
You need to implement the push and pop functions. The rest of the program will handle the input and output operations.
Input: Queries = 2 1 5 2 2
Output: -1 5 -1
Explanation: 2: Pop from an empty queue ? Output: -1 ? Queue: {}. 1 5: Push 5 into the queue ? Queue: {5}. 2: Pop and print the front element (5) ? Queue: {}. 2: Pop from an empty queue ? Output: -1
Input: Queries = 1 10 1 20 2 1 30 2 2
Output: 10 20 30
Explanation: 1 10: Push 10 into the queue ? Queue: {10}. 1 20: Push 20 into the queue ? Queue: {10, 20}. 2: Pop and print the front element (10) ? Queue: {20}. 1 30: Push 30 into the queue ? Queue: {20, 30}. 2: Pop and print the front element (20) ? Queue: {30}. 2: Pop and print the front element (30) ? Queue: {}
Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)
- 1 <= number of query<= 10^5
- 0 <= x <= 10^5
