A Common-Sense Guide to Data Structures and Algorithms in JavaScript, Volume 1

Chapter 6

These are the solutions to the exercises found in the section ​Exercises​.

1. In Big O notation, 2N² + 2N + 1 gets reduced to O(N²). After getting rid of all the constants, we’re left with N² + N, but we also drop the N since it’s a lower order than N².

2. Since log N is a lower order than N, it’s simply reduced to O(N).

3. The important thing to note here is that the function ends as soon as we find a pair that sums to 10. The best-case scenario, then, is when the first two numbers add up to 10, since we can end the function before the loops even get underway. An average-case scenario may be when the two numbers are somewhere in the middle of the array. The worst-case scenarios are when there aren’t any two numbers that add up to 10, in which ...