All Topics Quiz

Timer: 0s

Question 1

What is the base condition for merge sort in a doubly linked list?

When head is null or head.next is null

When list size is even

When head.prev is null

When tail.next is null

Question 2

What is the purpose of the split function in merge sort on DLL?

To reverse the list

To split the list into two halves

To delete the middle node

To find and move the max node

Question 3

What is the time complexity of merge sort on a doubly linked list?

O(n)

O(n log n)

O(n²)

O(log n)

Question 4

Which traversal direction(s) can be used in a doubly linked list?

Only forward

Only backward

Both forward and backward

None

Question 5

What is the key operation during the merge step of merge sort for DLL?

In-place reversal

Merge two sorted lists

Delete duplicates

Apply stack-based recursion

Question 6

What does a Minimum Stack track in addition to values?

Stack size

Current minimum value

Average of all values

Maximum value

Question 7

Which additional data structure is often used in implementing a minimum stack?

Queue

Set

Auxiliary stack

Tree

Question 8

What is the time complexity for retrieving the minimum element in a minimum stack?

O(n)

O(log n)

O(1)

O(n²)

Question 9

What happens during a push operation in a minimum stack?

Only push onto one stack

Push only if smaller

Push into both main and auxiliary stacks

Always push null values

Question 10

How does a pop operation affect the minimum stack?

Pops only from main stack

Pops only from auxiliary stack

Pops from both stacks

Pops from queue

Question 11

In the celebrity problem, how many people must a celebrity know?

All

One

None

Half

Question 12

Who must know the celebrity?

Nobody

Only friends

Everyone else

Only people who are not celebrities

Question 13

What is the optimal time complexity of solving the celebrity problem?

O(n)

O(n²)

O(log n)

O(1)

Question 14

Which data structure is commonly used in the brute-force solution of the celebrity problem?

Queue

Matrix

Tree

Graph

Question 15

Which condition identifies person A as not a celebrity when checking against B?

A knows B

B knows A

A doesn't know B

A is equal to B

Question 16

How many total moves are required to solve Tower of Hanoi with n disks?

2^n

2^n - 1

n²

Question 17

In the iterative version, what determines whether a move is between source and destination?

Disk size

Iteration number

Whether n is even or odd

Current stack size

Question 18

What is the data structure used to simulate Tower of Hanoi iteratively?

Queue

Stack

Tree

Graph

Question 19

What is the first move in iterative Tower of Hanoi when n is even?

Source → Destination

Source → Auxiliary

Destination → Auxiliary

Auxiliary → Source

Question 20

What happens if the move is not legal in iterative Tower of Hanoi?

Skip

Move smaller disk only

Move larger disk

Terminate

Question 21

What does the stock span value indicate?

Highest price

How many consecutive days price was higher

Days until next price drop

Number of days the price was less than or equal

Question 22

What data structure is used for efficient stock span calculation?

Queue

Stack

Heap

Set

Question 23

What is the worst-case time complexity for calculating spans for n days?

O(n log n)

O(n²)

O(n)

O(log n)

Question 24

What is pushed onto the stack during the stock span algorithm?

Prices only

Spans

Indices

Both prices and indices

Question 25

When is the stack popped during the stock span calculation?

When the current price is lower than the top

When the current price is higher than the top

When stack is full

Never

Question 26

What is stored in each node of a priority queue using DLL?

Value only

Priority only

Value and priority

Index

Question 27

What operation determines the ordering of elements in a DLL-based priority queue?

Arrival time

Priority comparison

Random sorting

Stack order

Question 28

Where is the highest priority node placed in a max-priority queue?

At the end

At the front

Randomly

Middle

Question 29

Which method is efficient for inserting into a sorted DLL priority queue?

Insert at head

Linear search for position

Insert at tail

Binary search

Question 30

What is the time complexity for insertion in a sorted DLL priority queue?

O(log n)

O(n)

O(1)

O(n²)

Question 31

Which technique allows sorting an array in-place without extra space?

Quick Sort

Merge Sort

Counting Sort

Radix Sort

Question 32

What is the space complexity of in-place sorting?

O(1)

O(log n)

O(n)

O(n²)

Question 33

Which sorting algorithm is not in-place?

Selection Sort

Heap Sort

Merge Sort

Insertion Sort

Question 34

What does "in-place" mean in sorting context?

No comparisons

Uses O(1) extra space

Requires recursion

Uses stack

Question 35

Can quicksort be modified to use in-place sorting?

Yes

Only for integers

Only if array is sorted

Question 36

What is the goal of the sliding window maximum problem?

Find min element

Find max in each window

Count window elements

Sum all elements

Question 37

Which data structure is optimal for solving sliding window maximum?

Stack

Heap

Queue/Deque

Tree

Question 38

What is the time complexity using deque for sliding window maximum?

O(n log n)

O(n)

O(n²)

O(n³)

Question 39

When is an index removed from the front of the deque?

When it holds min

When it's out of window

When it is repeated

When it's not the last

Question 40

What is stored in deque in sliding window algorithm?

Values

Indices

Windows

Maximums only

Question 41

Stack permutations are related to which type of traversal?

Preorder

Inorder

Stack simulation

DFS only

Question 42

Which condition must be met for a sequence to be a valid stack permutation?

Elements in reverse

Order of popping matches permutation

No repeats

Even number of elements

Question 43

In recovering BST, what data is required?

Parent pointers

Inorder traversal

Postorder traversal

Level order traversal

Question 44

How many nodes are swapped in a BST that needs recovery?

All

Question 45

What is the key step in recovering a BST with two swapped nodes?

Delete and reinsert

Rebuild BST

Identify and swap back

Change root only

Question 46

Which traversal is used in Top View of a binary tree?

DFS

Inorder

Level Order + Horizontal Distance

Postorder

Question 47

In Bottom View, which node is preferred at a horizontal distance?

Topmost

Leftmost

Rightmost

Bottommost

Question 48

What is the key value stored to distinguish positions in views?

Depth

Height

Horizontal Distance

Parent Value

Question 49

Right View of a tree can be extracted using which traversal method?

BFS right to left

DFS right first

DFS left first

Postorder

Question 50

What is required for Left View of a tree?

Preorder

Maximum level tracking

Inorder

Postorder

Question 51

Vertical order traversal uses which two parameters?

Level and index

Horizontal distance and level

Height and depth

Stack and queue

Question 52

What data structure is used to group nodes by horizontal distance?

Stack

TreeSet

HashMap or TreeMap

Queue

Question 53

What traversal ensures proper grouping in vertical order?

DFS

BFS with coordinates

Postorder

Inorder

Question 54

What order is required when multiple nodes have the same (hd, level)?

Max first

Left to right

Top to bottom

Any order

Question 55

In vertical traversal, nodes in same column are sorted by:

Node value only

Node height only

Level and then value

Parent order

Question 56

What are the three parts of boundary traversal?

Root, Right, Leaf

Left boundary, Leaves, Right boundary

Top, Bottom, Leaves

Only Leaves

Question 57

In which order are the boundary nodes printed?

Left to right

Top to bottom

Clockwise

Anti-clockwise

Question 58

Which nodes are excluded in left/right boundary traversal?

Nulls

Root

Leaf nodes

All nodes

Question 59

What traversal is used for collecting leaves?

Postorder

Inorder

Any DFS

BFS only

Question 60

Can a node be repeated in boundary traversal?

Yes, always

Yes, only root

Yes, leaves can repeat

Question 61

Which data structure is used for BFS?

Stack

Queue

Deque

Priority Queue

Question 62

DFS can be implemented using:

Stack or Recursion

Queue

Set only

TreeMap

Question 63

What is the time complexity of BFS/DFS in an adjacency list?

O(V)

O(E)

O(V+E)

O(V×E)

Question 64

Which traversal guarantees shortest path in unweighted graph?

DFS

Dijkstra

BFS

Question 65

DFS is best suited for:

Finding shortest path

Finding connected components

Level order printing

Sorting by level

Question 66

Dial's Algorithm is used for graphs with:

Negative weights

Only 0-1 weights

Small non-negative integer weights

Undirected graphs only

Question 67

Which data structure is central in Dial's Algorithm?

Priority queue

Min Heap

Bucket array

Stack

Question 68

Dial's algorithm is a variation of:

DFS

Prim's

Bellman-Ford

Dijkstra's

Question 69

Time complexity of Dial's algorithm is:

O(V+E)

O(E log V)

O(W × V) where W is max edge weight

O(V²)

Question 70

Dial's algorithm is best used when:

Edge weights are floating point

All edge weights are 1

Edge weights are integers in small range

Graph is unconnected

Question 71

What kind of graphs does Bellman-Ford work on?

Undirected only

Weighted with no cycles

Weighted with negative edges

Trees only

Question 72

What is the time complexity of Bellman-Ford algorithm?

O(V+E)

O(E log V)

O(VE)

O(V²)

Question 73

How many times are edges relaxed in Bellman-Ford?

V-1

E-1

Question 74

What does Bellman-Ford detect that Dijkstra cannot?

Cycles

Negative weight cycles

Minimum spanning tree

DFS path

Question 75

Which condition breaks Bellman-Ford early?

All edge weights same

No changes in any edge relax

Heap is empty

All visited

Question 76

Which graph type supports topological sorting?

Undirected

DAG

Any weighted graph

Tree

Question 77

Which algorithm can be used for topological sort?

Dijkstra

DFS

Kruskal

Prim

Question 78

What happens if a cycle exists in a graph to be topologically sorted?

Sorts partially

Skips cycle

Not possible

DFS fails

Question 79

In Kahn's algorithm, nodes with what indegree are added to queue first?

Maximum

One

Zero

Two

Question 80

How many topological orders are possible for a graph?

One

Zero

Depends on structure

Infinite