Page 48 - CT_AI_Class-5

A Buggy Algorithm Spot the Problem ALGORITHM IN REAL-LIFE

As you now understand what algorithms are, you might be surprised to know how
Step Action
many algorithms you encounter every single day.
1 Put bread in the toaster
2 Take the toast out of the toaster Here are a few examples of algorithm in real-life:

3 Turn the toaster on Example 1: ATM Machine

4 Spread butter on the toast When you use an Automatic Teller Machine (ATM) to withdraw money, the ATM
5 Eat the toast follows a specific algorithm to verify your identity and check that you have enough
money in your account. Here is the simplified algorithm an ATM follows:
Solution: Step 2 and Step 3 are in the wrong order. You should turn the toaster ON Step 1 User inserts debit card.
before you take the bread out. The corrected order should be: 1 → 3 → 2 → 4 → 5.
Step 2 ATM asks for PIN (secret number).
Testing Your Algorithm
Step 3 Is PIN correct?
After fixing a bug, one should always test his algorithm again. Testing means If NO: Show error and eject card.
checking that the algorithm works correctly with different situations and giving the
expected result. If YES: Continue.

Step 4 User selects amount to withdraw.
21 st
Century #Critical Thinking Step 5 Is enough money in account?
FINDING THE BUG AND FIXING Skills

THE ALGORITHM If NO: Show error.

A robot chef tried to make a sandwich for Kavya, but something went wrong. The sandwich If YES: Dispense cash.
was not made properly because the steps were not in the correct order. Can you find the bug? Step 6 Print receipt and eject card.

Here is the algorithm given to the robot:
1. Get two slices of bread from the bag 2. Eat the sandwich
Example 2: Search Engine
3. Open the refrigerator 4. Take out the cheese and tomato

5. Close the refrigerator 6. Put one slice of bread on the plate When you search something on a search engine
like Google, it uses a smart set of steps to find useful
7. Put the cheese on the bread 8. Put the sliced tomato on the cheese
information for you. It looks at your search words,
9. Place the second slice of bread on top 10. Cut the tomato in slices
related popular pages and past searches. It gives you
The bug is found and after fixing the steps, kavya finally got her tasty sandwich.
results in just a second.
Based on the above case, answer the following questions:

1. What was the bug in the algorithm?
Example 3: Traffic Lights

Traffic lights also follow an algorithm. They systematically
2. Why is it important to follow the correct order of steps in an algorithm? change from red to yellow to green in a fixed order and stay on

for a certain time. Even in busy cities, more advanced algorithms

46 Artificial Intelligence (CT & AI)-V