You're on assignment part 2/3 for this lesson.
Logarithm Quiz
Exponents grow very quickly, and logarithms grow very slowly. A logarithm is the inverse of an exponent.
Generally speaking, it's nice when we can write code that uses log(n) time to run, where n is the amount of data to process. For example, let's say we have a list of 1,000,000 users, and we want to write an algorithm that finds the user with the most followers.
If it takes 1 millisecond to check one user (let's just pretend), a linear algorithm would take 1,000,000 milliseconds, or about 16 minutes and 40 seconds.
A quadratic algorithm (exponent) would take 1,000,000,000,000 milliseconds, or about 31.7 years.
However, a logarithmic algorithm would only take 20 milliseconds! Here's a table to illustrate the difference:
| Input Size | Linear (n*2) |
Quadratic (n^2) |
Log (log2(n)) |
|---|---|---|---|
| 10 | 20 ms | 100 ms | 3 ms |
| 100 | 200 ms | 10,000 ms | 7 ms |
| 1,000 | 2,000 ms | 1,000,000 ms | 10 ms |
| 10,000 | 20,000 ms | 100,000,000 ms | 14 ms |
| 100,000 | 200,000 ms | 10,000,000,000 ms | 17 ms |
| 1,000,000 | 2,000,000 ms | 1,000,000,000,000 ms | 20 ms |