Unit1 : 4.Creating a merge sort program

Multiple Choice

What is the first phase of a merge sort?

• A. Swapping out-of-order neighbours

• B. Repeatedly dividing the list into halves until single items remain

• C. Picking the smallest and moving it to the front each time

• D. Randomly shuffling, then checking order

Multiple Choice

Which algorithm can often stop early when the list is already almost sorted (because no swaps happen in a pass)?

• A. Merge sort

• B. Bubble sort

• C. Both

• D. Neither

Multiple Choice

For a very large, jumbled list, which algorithm usually finishes faster?

• A. Merge sort

• B. Bubble sort

• C. Both the same

• D. Neither can sort large lists

Multiple Choice

Which description pairs each algorithm with its main idea?

• A. Bubble: split in halves; Merge: swap neighbours

• B. Bubble: compare/swap adjacent items; Merge: split list into halves then merge in order

• C. Bubble: pick smallest and insert; Merge: random shuffle

• D. Bubble: divide-and-conquer; Merge: pick-and-place

Multiple Choice

Why is merge sort called a “divide and conquer” algorithm?

• A. It swaps neighbours until no swaps are needed

• B. It divides the list into smaller parts, processes them, then merges them back in order

• C. It randomises the list to avoid worst cases

• D. It always picks the smallest item and inserts it at the front

Multiple Choice

In merge sort, which step is the conquer phase?

• A. Splitting the list into halves repeatedly

• B. Choosing a pivot and partitioning

• C. Merging sorted sublists into one ordered list

• D. Swapping adjacent items

Multiple Choice

What is a real-world benefit of sorting data mentioned on the slide?

• A. It helps you analyse/search quickly (e.g., find a song by artist)

• B. It increases image colour depth

• C. It automatically encrypts results

• D. It always reduces file size

Multiple Choice

To find what films were released in a given year most efficiently, which field should you sort by?

• A. Runtime

• B. Title (A–Z)

• C. Viewer rating

• D. Release year

Multiple Choice

When does the algorithm stop splitting into sub-lists?

• A. After a fixed number of splits

• B. When a sub-list has length 1 (base case)

• C. When the first item is smallest

• D. When list length > 1

Multiple Choice

What is the role of MERGE sub-list and SORT followed by REPEAT UNTIL list is sorted?

• A. Compare and swap adjacent items

• B. Pick the smallest and insert at the front

• C. Combine sub-lists while ordering them until one fully sorted list remains

• D. Randomly shuffle until order appears