Example Writeup

Homeworks should be written up clearly and succinctly; you may lose points if your answers are unclear or unnecessarily complicated. This is an example of what we are looking for.

Simple Question

Question: In big-O notation, how many contiguous subsequences are there of a list of $n$ numbers?

Answer: There are $O(n)$ choices for the starting position of the subsequence and $O(n)$ choices for the ending position. Therefore, there are $O(n^2)$ possible contiguous subsequences.

Here, using words is precise enough and easy to read.

More Involved Question

Question: Suppose you flip a sequence of independent fair coins until you get heads, and on each preceding tails flip, you roll a 6-sided fair dice. What is the expected value of the sum of the die?


General guidelines: