Consider the following randomly ordered numbers stored in a list: 106, 104, 106, 102, 105, 10 Show the content

Question

Q. Consider the following randomly ordered numbers stored in a list: 106, 104, 106, 102, 105, 10 Show the content of list after the First, Second and Third pass of the selection sort method used for arranging in ascending order. Note : Show the status of all the elements after each pass very clearly encircling the changes.

(OR)

Consider the following randomly ordered numbers stored in a list: 106, 104, 106, 102, 105, 107 Show the content of list after the First, Second and Third pass of the bubble sort method used for arranging in descending order. Note : Show the status of all the elements after each pass very clearly encircling the changes.

CBSECBSE Class XII Board 2019Subjective· 3mImportance★★★★★

🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

Part (a)Concept understanding — Sorting Applications

Sorting Applications: Why Order Matters

Think about the last time you searched for a song on your phone. You probably scrolled through an alphabetical list, or sorted by "most played" or "recently added." You didn't notice the work happening behind the screen — but without sorting, you'd be staring at a random jumble of thousands of songs, hunting for one name.

That's the core idea. Sorting is the process of arranging data in a meaningful order — alphabetical, numerical, chronological, or by any other criterion. And sorting applications are simply the real-world uses of this process, from the obvious to the invisible.

The Everyday Intuition

Imagine a pile of 500 exam answer sheets on a teacher's desk. If they're in random order, finding a specific student's paper takes forever. If they're sorted alphabetically by name, you can jump to the right section in seconds. If they're sorted by roll number, even faster.

Now scale that up. A bank with millions of accounts. A hospital with thousands of patient records. A railway reservation system with lakhs of bookings. Without sorting, none of these systems can function efficiently. Sorting is the invisible hand that turns chaos into usable order.

The Precise Meaning

In computing and data management, sorting means rearranging a collection of items so that they follow a defined sequence. The sequence could be:

Ascending (smallest to largest, A to Z, earliest to latest)
Descending (largest to smallest, Z to A, latest to earliest)
Custom (by priority, by category, by any rule you define)

A sorting application is any system, tool, or process that uses sorting to achieve a practical goal. The sorting itself is usually done by an algorithm — a step-by-step procedure — but as a commerce or humanities student, you don't need to know the algorithm's mechanics. What matters is why sorting is used and what it enables.

Why Sorting Matters

Important

Sorting is not about neatness. It is about speed and accessibility. A sorted list can be searched, compared, and analysed far faster than an unsorted one. This is the single most important idea to remember.

Consider these everyday examples:

E-commerce websites — When you filter products by "Price: Low to High" or "Customer Rating," the website is sorting thousands of items in real time. Without this, you'd scroll endlessly.
Bank statements — Transactions are sorted by date. You can instantly see your most recent purchase or check a specific month's activity.
Attendance registers — Names sorted alphabetically or by roll number. Finding a student takes seconds, not minutes.
Library catalogues — Books sorted by author, title, or subject. You can locate any book without walking through every shelf.
Exam results — Rank lists are sorted by marks (descending). The topper is at the top, not buried somewhere in the middle.

The Hidden Sorting

Many sorting applications are invisible to the user. When you log into a social media feed, the posts are sorted — by recency, by relevance, or by an algorithm that predicts what you'll engage with. When you search for a flight, the results are sorted by price, duration, or departure time. When a hospital schedules surgeries, patient records are sorted by urgency or time of booking. …

Part (b)Concept understanding — Bubble Sort Passes

Imagine you have a messy stack of exam answer sheets on your desk, and you need to arrange them in order of roll numbers — smallest on top, largest at the bottom. You could pick up the whole stack and try to sort it in one go, but that’s confusing. Instead, you decide to work in small, repeated steps: you compare just two adjacent sheets at a time, and if the top one has a larger roll number than the one below it, you swap them. Then you move down one position and compare the next pair. You keep doing this, from the top of the stack to the bottom, over and over again, until the entire stack is sorted.

That repeated journey from top to bottom is what a pass is in Bubble Sort. Each pass is one complete scan of the list, comparing each pair of neighbouring items and swapping them if they are in the wrong order. After the first pass, the largest element “bubbles up” to its correct position at the end — just like the biggest bubble rises to the surface in a glass of soda. After the second pass, the second-largest element settles into the second-last position, and so on.

Note

In Bubble Sort, the number of passes you need is always one less than the total number of items. For example, if you have 10 answer sheets, you will need at most 9 full passes to guarantee the list is sorted. This is because after each pass, one more element locks into its final place at the end, and the last remaining element automatically falls into the first position without needing a separate pass.

Why does this matter? Because each pass reduces the amount of work for the next one. After the first pass, you never have to look at the last element again — it’s already correct. After the second pass, you can ignore the last two elements, and so on. This shrinking of the “active” part of the list is what makes Bubble Sort efficient enough for small datasets, even though it is slow for large ones. …

Start your 14-day free trial to unlock the full solution →

Part (a)

Selection sort, ascending, on [106, 104, 106, 102, 105, 10]. Each pass finds the smallest value in the unsorted part and swaps it into the next front position.

Pass 1: smallest is 10 (last) → swap to front: [10, 104, 106, 102, 105, 106]
Pass 2: smallest of the rest is 102 → swap to index 1: [10, 102, 106, 104, 105, 106] …

Start your 14-day free trial to unlock the full solution →

Part (a) selection sort ascending: passes give [10,104,106,102,105,106], [10,102,106,104,105,106], [10,102,104,106,105,106].

Part (b) bubble sort descending: passes give [106,106,104,105,107,102], [106,106,105,107,104,102], [106,106,107,105,104,102].

Part (a)

Selection sort works by repeatedly selecting the smallest element of the unsorted region and placing it at the front of that region. The list is [106, 104, 106, 102, 105, 10].

Pass 1 — scan indices 0..5, the minimum is 10 (at the end); swap it with the first element → [10, 104, 106, 102, 105, 106].
Pass 2 — scan indices 1..5, the minimum is 102; swap it into index 1 → [10, 102, 106, 104, 105, 106].
Pass 3 — scan indices 2..5, the minimum is 104; swap it into index 2 → [10, 102, 104, 106, 105, 106].

You can verify the trace:

data = [106, 104, 106, 102, 105, 10]
n = len(data)
for i in range(3):                 # first three passes
    mn = i
    for j in range(i + 1, n):
        if data[j] < data[mn]:
            mn = j
    data[i], data[mn] = data[mn], data[i]
    print("Pass", i + 1, ":", data)

Pass 1 : [10, 104, 106, 102, 105, 106]
Pass 2 : [10, 102, 106, 104, 105, 106]
Pass 3 : [10, 102, 104, 106, 105, 106] …

Start your 14-day free trial to unlock the full solution →

Same / Similar Concept — real previous-year questions on the same or a closely similar concept, not this exact question.

CBSE 2023Set 91/11 markMCQ
$Q. Fill in the blank. .............. function is used to arrange the elements of a list in ascending order.$
(a) sort()
(b) arrange()
(c) ascending()
(d) asort()
›Reveal solutionSolution

In Python, the sort() function is the correct method to arrange the elements of a list in ascending order.

When you work with lists in Python, one of the most common tasks is putting the elements in order. The NCERT Computer Science textbook for Class 11 introduces this clearly: the method that does this job is sort(). It is a built-in method attached directly to list objects.

Think of it this way — Python gives every list a set of tools it can use, and sort() is one of them. When you call my_list.sort(), Python rearranges the items inside that list so they go from smallest to largest (or, for strings, in alphabetical order). The list itself changes permanently; this is called "sorting in place."

The other options in the question are not correct for Python lists. arrange() is not a Python function at all. ascending() might sound logical, but Python does not have a method by that name. asort() is also not a standard Python function — though some other programming languages or libraries use something similar, the NCERT syllabus sticks to Python's standard library. …
Start your 14-day free trial to see the full solution →

Part (a)

🎓Unlock everything free for 14 days

Unlock everything free for 14 days