The Challenge
Finally, you have your hands on the blueprints to the bank. You can see that on the blueprints there are only certain routes which you can take in order to avoid triggering the security alarms at 3:23AM (prime bank robbing time).
You need to plan your route carefully to get to the vault as quickly as possible and avoid detection. Luckily, someone has added the number of footsteps it takes along the routes on the blueprints!
First you need to go into the reception cabinet to obtain the keys to the HR office which contain employee records. Inside the records you will find the password to the computer of your accomplice who works in foreign exchange. Your accomplice has left you a key to access the cupboard by the Business Analyst’s desk. You need to find a file containing information about the top-secret floor – including the passcode to the vault.
Can you find a route that takes no more than 217 steps?
The Solution
Did you manage to find a solution under 217 steps? You’ve just solved a graph theory problem! Graph theory is the mathematical study of graphs which consist of vertices (or nodes, such as the Coffee Machine in the maze) which are connected by edges.
This problem in particular is known as the shortest path problem – we want to find a path between two nodes so that the total is minimised!
See the image below for the shortest path which takes exactly 217 steps.
The shortest route (with a total of 217) is: Entrance, Reception Desk (12), Reception Cabinet (9), Fish Tank (18), Microwave1 (7), Recruitment Materials (16), Employee Records (6), Training Materials (18), Head of HR Seat (10), Foreign Exchange (25), Microwave2 (36), Fridge (8), Frontend Engineers (11), Business Analysts (3), Data Analysts (19), Drinks Machine (14), VAULT (5).
how 2 rob a bank 