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Data Structures and Algorithms → Trees 11

B-tree is?
Self-balancing, each node can have more than 2 children
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B-tree was invented to?
Minimize disk accesses in secondary storage
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In B-tree of order m, each internal node has at most how many keys?
m-1
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B-tree: all leaves are at?
Same level (same depth)
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Key difference B-tree vs B+ tree?
B+ stores data only at leaves; B-tree at all nodes
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Height of perfect binary tree with 15 nodes?
3
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Maximum nodes in binary tree of height 4?
31
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Number of leaf nodes in perfect binary tree of height h?
2^h
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Preorder traversal used for?
Creating copy of tree (serialization)
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Maximum leaf nodes in binary tree of height h?
2^h
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Height of complete binary tree with 8 nodes?
3
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Data Structures and Algorithms → Introduction to DSA 26

B+ tree leaf nodes are connected as?
Linked list of leaves
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Tree degree?
Maximum of all node degrees
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Which traversal used for tree deletion (delete children before parent)?
Postorder
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What is a degenerate BST?
All nodes have one child (skewed like linked list)
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In BST, all operations on balanced tree?
O(log n)
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Siblings in tree are nodes that?
Share same parent
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Ancestors of a node are?
On path from root to node (higher in hierarchy)
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Internal node is?
Node with at least one child
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What is a forest?
A set of trees
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In Python BST, the Node class attributes are?
data, left, right, parent
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What is an undirected graph?
Edges have no direction (bidirectional)
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What is a directed graph?
Edges have direction (one-way)
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What is a null graph?
No edges
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What is a cyclic graph?
At least one cycle exists
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What is an acyclic graph?
No cycles
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Weighted graph?
Edges have numerical weights
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What is a connected graph?
Every pair has path between them
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What is a complete graph?
Every pair of vertices has an edge
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What is a multigraph?
Two or more edges between same pair of nodes
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Degree of a vertex?
Number of vertices connected by edges
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Two vertices are neighbours if?
Edge exists between them
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What is a path in a graph?
Sequence of alternating nodes and edges (successive nodes connected)
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What is a simple path?
No vertex repeated
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What is a bridge in a graph?
Edge whose removal disconnects graph
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What is BFS?
Level-by-level traversal using queue
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First step in BFS?
Put any vertex at back of queue
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Data Structures and Algorithms → Binary Search Tree 1

Inorder traversal of BST gives?
Sorted ascending order
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Data Structures and Algorithms → Graphs 2

A graph is?
Non-linear with vertices and edges
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In BFS after dequeuing a vertex?
Visit all adjacent unvisited, enqueue them
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