Tree Data Structure: Terminology and Basic Concepts

Tree ek non-linear, hierarchical data structure hota hai jisme data elements nodes ke roop me arranged hote hain aur unke beech parent-child relationships hoti hain. Linear data structures (array, linked list) me elements sequential hote hain, jabki trees hierarchical information (jaise file directories, organizational charts, XML/HTML DOM trees) ko model karte hain.

Core Tree Terminology

• Root Node: Tree ka sabse top-most node jiska koi parent nahi hota (Tree me exactly 1 root hoti hai).
• Edge: Do nodes ke beech ki connecting link (directional pointer). N nodes ke tree me exactly N - 1 edges hoti hain.
• Parent & Child: Agar node A se edge node B tak ja rahi hai, toh A parent hai aur B child hai.
• Siblings: Same parent ke children nodes siblings kehlate hain.
• Leaf Node (Terminal Node / External Node): Aise nodes jinka koi child nahi hota (Degree = 0).
• Degree of a Node: Us node ke total number of children.
• Degree of a Tree: Tree ke sabhi nodes me se maximum degree.
• Depth of a Node: Root node se lekar us node tak path me number of edges. (Root ki depth = 0).
• Height of a Node: Us node se lekar kisi deepest leaf node tak longest path me number of edges.
• Height of a Tree: Root node ki height (ya tree ka maximum level).

Level 0 (Root)               [ A ]
                            /     \
Level 1                 [ B ]     [ C ]
                       /     \         \
Level 2            [ D ]     [ E ]     [ F ]

Nodes: A, B, C, D, E, F (Total = 6)
Edges: 5 (N - 1)
Leaves: D, E, F (Degree = 0)
Internal Nodes: A, B, C
Height of Tree: 2

Agli post me hum cover karenge Binary Trees: Types and Properties.