In a circular queue of capacity 7, assume front points to the first element and rear points to the next insertion position. If front = 4 and rear = 1, how many elements are currently in the queue?
With rear defined as the next insertion position, the number of elements is (rear - front + capacity) % capacity = (1 - 4 + 7) % 7 = 4. The occupied indices are 4, 5, 6, and 0.
What is the result of using a single stack to process the string "GATE2025" by pushing each char and then popping all chars?
A stack reverses the order of input items (LIFO). Reversing "GATE2025" gives "5202ETAG".
Which application explicitly requires a Queue data structure?
BFS uses a Queue to explore vertices level-by-level in FIFO order. DFS and Call Stacks use a Stack.
Calculate the result of postfix expression: 8 2 / 3 * 4 +:
8 / 2 = 4. 4 * 3 = 12. 12 + 4 = 16.
Which of the following operations on a Python collections.deque object run in O(1) time complexity?
All four push/pop operations at both ends of a deque execute in constant O(1) time.