Tree Structure: Hierarchy

Tree Structure problems involve hierarchical relationships where persons have managers and subordinates. You must build a tree (directed graph) from clues about reporting relationships, departments, and roles. These problems test graph construction and navigation skills.

10Worksheets
200+Practice Questions
IntermediateDifficulty
2-3 hoursHours to Master

Introduction to Tree Structure: Hierarchy

Tree Structure problems involve hierarchical relationships where persons have managers and subordinates. You must build a tree (directed graph) from clues about reporting relationships, departments, and roles. These problems test graph construction and navigation skills.

Prerequisites

Understanding of manager/subordinate relationships Tree/graph concepts Parent-child relationship in hierarchy Root node identification
Why This Matters: Tree Structure problems appear in 1-2 questions in Banking PO and SSC exams. They test organizational reasoning and tree traversal.

How to Solve Tree Structure: Hierarchy Problems

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Step 1: List all persons in the hierarchy

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Step 2: Identify the root (top-level manager) from clues

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Step 3: Add each reporting relationship as an edge (manager → subordinate)

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Step 4: Ensure no cycles exist (pure tree structure)

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Step 5: Assign departments and roles based on clues

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Step 6: Answer questions about direct reports, managers, or chain of command

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Step 7: Verify all relationships are satisfied

Pro Strategy: Draw the tree with the root at the top. Add each reporting relationship as a directed edge. Ensure each person has exactly one manager (except root). Use levels to track hierarchy depth.

Example Problem

Example: Six employees in a hierarchy. A and B report to M. C and D report to A. E reports to B. F reports to C. Who is the direct manager of F? Solution: Step 1: List persons: M, A, B, C, D, E, F Step 2: Root: M (A and B report to M) Step 3: Build tree: M → A, M → B; A → C, A → D; B → E; C → F Step 4: F reports to C Answer: C is manager of F

Pro Tips & Tricks

  • The root has no manager (top-level)
  • Each non-root person reports to exactly one manager
  • Direct reports are immediate subordinates
  • Indirect reports are subordinates through intermediate managers
  • Level 1 = root, Level 2 = direct reports, etc.
  • Use arrows pointing from manager to subordinate

Shortcut Methods to Solve Faster

If X reports to Y, then Y is manager of X
The root is the only person without a manager
Leaves are persons with no subordinates
Path from root to a person shows the reporting chain
Number of levels = maximum distance from root to leaf + 1

Common Mistakes to Avoid

Creating cycles in the hierarchy
Giving a person multiple managers
Forgetting that a person can have multiple subordinates
Misidentifying the root (top-level manager)

Exam Importance

Tree Structure: Hierarchy is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
1-2 questions
BANKING PO
1-2 questions
RAILWAYS RRB
1-2 questions
CAT
0-1 questions
INSURANCE
1-2 questions

Ready to Master Tree Structure: Hierarchy?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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