DSA

What is a balanced binary search tree? a) A binary search tree where the height of the left and right subtrees differ by no more than one b) A tree where all leaves are at the same level c) A binary tree with equal numbers of left and right children d) A tree where all […]

Which algorithm is used to detect a negative cycle in a graph? a) Bellman-Ford Algorithm b) Dijkstra’s Algorithm c) Floyd-Warshall Algorithm d) Prim’s Algorithm Answer: a) Bellman-Ford Algorithm Explanation: The Bellman-Ford algorithm is used to detect negative weight cycles in a graph. By running the algorithm for one additional iteration beyond the number of vertices,

What is the main advantage of a doubly linked list over a singly linked list? a) Allows for traversal in both directions b) Uses less memory c) Easier to implement d) Supports faster sorting Answer: a) Allows for traversal in both directions Explanation: The main advantage of a doubly linked list over a singly linked

What is the in-order traversal of a binary search tree (BST)? a) Left, Root, Right b) Root, Left, Right c) Right, Left, Root d) Left, Right, Root Answer: a) Left, Root, Right Explanation: In-order traversal of a binary search tree (BST) visits nodes in the following order: left subtree, root, and then right subtree. This

What is the space complexity of Merge Sort? a) O(1) b) O(log n) c) O(n) d) O(n log n) Answer: c) O(n) Explanation: The space complexity of Merge Sort is O(n) because it requires additional space for the temporary arrays used to merge the sorted subarrays. During the merging process, the algorithm creates a new

What is a hash collision in a hash table? a) When two keys hash to the same index b) When two keys have the same value c) When two values occupy the same memory address d) When two keys have the same length Answer: a) When two keys hash to the same index Explanation: A

What is a perfect binary tree? a) A binary tree where all levels are completely filled b) A binary tree with only one level c) A binary tree with no leaf nodes d) A binary tree with an equal number of left and right nodes Answer: a) A binary tree where all levels are completely

In a linked list, what is the time complexity of accessing an element by its index? a) O(1) b) O(n) c) O(log n) d) O(n log n) Answer: b) O(n) Explanation: Accessing an element by its index in a linked list takes O(n) time because linked lists do not provide direct access to elements. To

What is a red-black tree? a) A self-balancing binary search tree where each node has an extra color attribute b) A binary heap with two colors c) A balanced AVL tree with different color properties d) A linked list where each node has a color Answer: a) A self-balancing binary search tree where each node

What is a deque (double-ended queue)? a) A queue where elements can be added or removed from both ends b) A stack where elements are added at the top c) A priority queue where elements are sorted d) A linked list where each element points to the next Answer: a) A queue where elements can

Which of the following algorithms is used to find the shortest path in a graph with negative weights? a) Dijkstra’s Algorithm b) Bellman-Ford Algorithm c) Kruskal’s Algorithm d) Floyd-Warshall Algorithm Answer: b) Bellman-Ford Algorithm Explanation: The Bellman-Ford algorithm is used to find the shortest path in graphs with negative weights. Unlike Dijkstra’s algorithm, Bellman-Ford can

What is the time complexity of inserting an element into a sorted linked list? a) O(1) b) O(log n) c) O(n) d) O(n log n) Answer: c) O(n) Explanation: Inserting an element into a sorted linked list has a time complexity of O(n) because it requires traversing the list to find the correct insertion point.

What is a spanning tree of a graph? a) A subgraph that includes all the vertices of the graph and is a tree b) A subgraph that contains only leaf nodes c) A graph where all edges have equal weights d) A tree where every vertex has the same degree Answer: a) A subgraph that

Which sorting algorithm is considered a comparison-based sort? a) Radix Sort b) Counting Sort c) Quick Sort d) Bucket Sort Answer: c) Quick Sort Explanation: Quick Sort is a comparison-based sorting algorithm, meaning it sorts elements by comparing them to one another. The efficiency of Quick Sort is based on how well the pivot element

Which data structure is used to implement a LIFO (Last In, First Out) buffer? a) Stack b) Queue c) Priority Queue d) Deque Answer: a) Stack Explanation: A stack is used to implement a LIFO (Last In, First Out) buffer, meaning the last element added to the stack is the first to be removed. This

What is a strongly connected component in a directed graph? a) A subgraph where every vertex is reachable from every other vertex b) A subgraph where all edges have the same weight c) A tree where all nodes have equal depth d) A graph where all vertices are isolated Answer: a) A subgraph where every

In a min-heap, where is the minimum element located? a) At the root b) At a leaf node c) In the middle of the heap d) At the last position Answer: a) At the root Explanation: In a min-heap, the minimum element is always located at the root. This is because a min-heap is a

Which of the following algorithms is used to detect a cycle in a graph? a) Depth-First Search (DFS) b) Breadth-First Search (BFS) c) Dijkstra’s Algorithm d) Kruskal’s Algorithm Answer: a) Depth-First Search (DFS) Explanation: Depth-First Search (DFS) is commonly used to detect cycles in a graph. By tracking visited nodes and using a recursive or

What is the primary difference between a stack and a queue? a) Stack is LIFO, while queue is FIFO b) Queue is LIFO, while stack is FIFO c) Stack allows multiple elements to be processed simultaneously d) Queue allows random access to elements Answer: a) Stack is LIFO, while queue is FIFO Explanation: The primary

What is the time complexity of searching for an element in a hash table with n elements? a) O(n) b) O(log n) c) O(1) d) O(n log n) Answer: c) O(1) Explanation: The time complexity of searching for an element in a hash table is O(1) on average. This is because hash tables use a

Which data structure is used to find the shortest path in an unweighted graph? a) Stack b) Queue c) Priority Queue d) Array Answer: b) Queue Explanation: Breadth-First Search (BFS), which uses a queue, is used to find the shortest path in an unweighted graph. BFS explores all vertices at the current level before moving

What is a complete graph? a) A graph in which every pair of vertices is connected by an edge b) A graph with no edges c) A tree with all nodes filled d) A graph with equal weights on all edges Answer: a) A graph in which every pair of vertices is connected by an

What is the time complexity of inserting an element into an unsorted array? a) O(n) b) O(1) c) O(log n) d) O(n log n) Answer: b) O(1) Explanation: Inserting an element into an unsorted array can be done in constant time O(1) by simply placing the new element at the end of the array. This

Which of the following data structures is non-linear? a) Array b) Linked List c) Stack d) Graph Answer: d) Graph Explanation: A graph is a non-linear data structure consisting of nodes (also called vertices) and edges connecting the nodes. It is used to represent networks, such as social networks or communication networks, where relationships between

What is the best case time complexity for bubble sort? a) O(n log n) b) O(n) c) O(n^2) d) O(1) Answer: b) O(n) Explanation: The best case time complexity for bubble sort is O(n). This occurs when the input array is already sorted, so no swaps are needed, and the algorithm only makes one pass