Implement a Queue using an Array. Queries in the Queue are of the following type:
(i) 1 x (a query of this type means pushing 'x' into the queue)
(ii) 2 (a query of this type means to pop element from queue and print the poped element)
Example 1:
Input:
Q = 5
Queries = 1 2 1 3 2 1 4 2
Output: 2 3
Explanation:
In the first test case for query
1 2 the queue will be {2}
1 3 the queue will be {2 3}
2 poped element will be 2 the
queue will be {3}
1 4 the queue will be {3 4}
2 poped element will be 3
Example 2:
Input:
Q = 4
Queries = 1 3 2 2 1 4
Output: 3 -1
Explanation:
In the second testcase for query
1 3 the queue will be {3}
2 poped element will be 3 the
queue will be empty
2 there is no element in the
queue and hence -1
1 4 the queue will be {4}.
Your Task :
You are required to complete the two methods push() which take one argument an integer 'x' to be pushed into the queue and pop() which returns a integer poped out from othe queue. If the queue is empty, it should return -1 on a pop operation.
Expected Time Complexity: O(1) for both push() and pop().
Expected Auxiliary Space: O(1) for both push() and pop().
Constraints:
1 <= Q <= 105
1 <= x <= 105
If you have purchased any course from GeeksforGeeks then please ask your doubt on course discussion forum. You will get quick replies from GFG Moderators there.
| lone_walker | 398 |
| 2isprime | 337 |
| Umakant_Dubey | 314 |
| rathindran | 262 |
| saiujwal13083 | 251 |
| saiujwal13083 | 889 |
| ppsvikhyat17 | 712 |
| lone_walker | 684 |
| generic_coder | 630 |
| NaveenGarg2 | 554 |
| blackshadows | 5448 |
| Ibrahim Nash | 5438 |
| akhayrutdinov | 5111 |
| mb1973 | 4976 |
| Quandray | 4752 |