Programmer's Picnic---Linear--Search

Programmer's Picnic — Live Zoom Lesson

Fun, short lessons for curious programmers — hands-on, friendly, and practical.

Zoom Lesson • Interactive • Recording available

Date: [Replace with date]
Time: [Replace with time & timezone]

Join Zoom Lesson See Agenda Contact on WhatsApp Materials & Code

Linear Search on Youtube

Topic: Algorithm picnic — Visualizing searching

Level: Beginner → Intermediate

Lesson Snapshot

Topic: Algorithm picnic — Visualizing linear search

Level: Beginner → Intermediate

Short description: Join us for a 40-minute interactive Zoom where we explain a compact algorithm, show pseudocode, implement it in Python , run a tiny demo, and finish with a 5-question MCQ lightning quiz.

Agenda

1. Welcome & quick icebreaker
2. Concept introduction & intuition
3. Pseudocode walk-through + dry run on whiteboard
4. Code implementations & live demo
5. MCQ quiz + recap
6. Q&A and next steps

Learning Outcomes

• Understand the algorithm's idea and when to use it.
• Read and follow pseudocode and dry-run examples.
• Implement the algorithm quickly in your preferred language.
• Spot basic complexity and possible optimisations.

Pre-work (Optional)

Please bring a laptop with a code editor or open browser console. If possible, paste the code snippets shared in the 'Materials' section into your editor before the meeting.

Left Linear Search

We'll do a whiteboard-style dry run on the sample array and annotate each swap step live.

Code — Implementations

Python

a = [7, 5, 1, 8, 5, 9, 5, 2]
print(a)
# a[3]=90
# print(a)
searchvalue=int(input("Enter value to search "))
n=len(a)
# print(f"n={n}")
# print(a[n-1])

position="Not found"
r=range(n)
for index in r:
    # print(index,a[index])
    if a[index]==searchvalue:
        position=index
        break
if position=="Not found":
    print(f"{searchvalue} is {position}")
else:
    print(f"{searchvalue} found at {position}")
  

Right Linear Search

We'll do a whiteboard-style dry run on the sample array and annotate each swap step live.

Code — Implementations

Python

a = [7, 5, 1, 8, 5, 9, 5, 2]
# 1,4 and 6
print(a)
searchvalue = int(input("Enter value to search "))
n = len(a)

position = "Not found"
r = range(n-1, -1, -1)
for index in r:

    if a[index] == searchvalue:
        position = index
        print(position)
        break
if position == "Not found":
    print(f"{searchvalue} is {position}")
else:
    print(f"{searchvalue} found at {position}")
  

You can copy-paste any snippet and run it during the live demo. We'll run the JS in the browser console for immediate visual feedback.

All Linear Search

We'll do a whiteboard-style dry run on the sample array and annotate each swap step live.

Code — Implementations

Python

a = [7, 5, 1, 8, 5, 9, 5, 2]
# 1,4 and 6
print(a)
searchvalue = int(input("Enter value to search "))
n = len(a)

positions = []
r = range(n-1, -1, -1)
for index in r:

    if a[index] == searchvalue:
        positions.append(n-1-index)
        print(positions)
        # break
        # A1,B2,C3.......X24,Y25,Z26   27-1=26
if len(positions) == 0:
    print(f"{searchvalue} is not found")
else:
    print(f"{searchvalue} found at {positions}")
  

Python Editor Take Quiz

Complexity & Notes

• Time complexity: O(n) worst-case, O(n) best-case O(1).
• Space complexity: O(1) (in-place).
• Good for: small arrays, unsorted data, teaching/learning steps.

Lightning Quiz — 5 MCQs

1. Best-case time complexity of Linear Search?

O(n²)
O(n)
O(1)

2. Is linear search stable?

Yes
No

3. Space complexity of insertion search?

O(n)
O(1)

4. Which input suits linear search best?

Large random arrays
Small random arrays

5. In the right search we moved in from the right. That is an example of:

Reverse loop
Forward loop

Next Steps & Resources

• Repo & code bundle: We will share a Google Drive / GitHub link during the Zoom.
• Recording: Will be available within 24 hours after the session.
• Homework: Implement a visualiser or convert the code to another language you prefer.

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Code on Github

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Join Zoom Lesson Contact on WhatsApp Take Quiz

Prepared by Champak Roy — Programmer's Picnic series.