Algo facts & stats

Question 1

Which sorting algorithm repeatedly swaps adjacent items that are out of order?

Accepted Answer

Bubble sort. Bubble sort passes through a list swapping neighbors, so large items bubble to the end.

Question 2

Which data structure follows last in, first out (LIFO)?

Accepted Answer

Stack. Like a stack of plates, the last item pushed onto a stack is the first removed.

Question 3

The word 'algorithm' comes from the name of which mathematician?

Accepted Answer

Al-Khwarizmi. It derives from the Latinized name of the 9th-century Persian mathematician Muhammad ibn Musa al-Khwarizmi.

Question 4

What is the time complexity of merge sort?

Accepted Answer

O(n log n). Merge sort splits the list in half repeatedly and merges, taking n log n time in all cases.

Question 5

Which data structure follows first in, first out (FIFO)?

Accepted Answer

Queue. A queue works like a line of people: the first to join is the first served.

Question 6

What is the worst-case time complexity of quicksort?

Accepted Answer

O(n²). Quicksort averages O(n log n) but degrades to O(n²) when pivots split the list very unevenly.

Question 7

What does Euclid's algorithm compute?

Accepted Answer

The greatest common divisor of two numbers. Euclid's algorithm repeatedly takes remainders to find the largest number dividing both inputs.

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