Zombie Survival

Decomposition: Break it down to build it up


Year 8 Computer Science

⚠ ZOMBIE APOCALYPSE ⚠

2 MINUTES

Write down everything you need to do to survive.

GO — right now. Don't organise it. Just write.

The Problem with Problems

Your chaotic list: hard to follow, hard to prioritise, easy to miss things.


The solution: decomposition


SURVIVE
├── Food
├── Shelter
├── Safety
├── Communication
└── Medical

Now each branch is a manageable sub-problem.

Decomposition

Breaking a complex problem into smaller sub-problems that can each be solved independently.


Food
├── Find sources
│ ├── Identify edible plants
│ ├── Locate supermarkets
│ └── Set up hunting traps
├── Preserve food
└── Purify water

Go deep until every leaf is a specific, actionable task.

Your Turn

Dependencies

Which sub-problems depend on each other?


Draw arrows between dependent branches (in a different colour). Label each: WHY?

CS Connection

Programmers decompose problems into functions.

find_food()
check_water_safe()
alert_nearby_survivors()
treat_injury(patient, injury_type)
locate_shelter(radius_km)

Each function solves exactly one sub-problem.

Key Takeaway

Decomposition turns an impossible problem into a list of solvable ones.

Every complex program is built by decomposing into functions — each solving exactly one sub-problem.
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