Feature #11: Generate Movie Viewing Orders
Explore how to generate every possible viewing order of movies in a Netflix marathon using a backtracking algorithm. Understand how to implement permutations efficiently and manage time and space complexity in Rust, preparing you for coding interviews focused on real-world problem-solving.
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Description
We want to offer marathons for our viewers. Each marathon will have a fixed set of movies catering to a specific taste. For a given marathon, different viewing orders of the movies will yield different user satisfaction results. We want to experiment (A/B testing) with different viewing orders of the same marathon.
Your task is to generate all the possible permutations of movies in a given marathon.
Let’s look at an example to better understand this:
Solution
To solve this problem, we will use the backtracking approach.
We will assume a backtrack function that takes the index of the first movie to consider as an argument backtrack(first).
-
If the first movie to consider has index
n, then that means that the current permutation is done. -
We will iterate over the marathon from index
firstto indexn - 1. -
We will place the
ith movie first in the permutation, that is,movies_list[first], movies_list[i] = movies_list[i], movies_list[first]. -
We will proceed to create all the permutations that start from the
ith movie:backtrack(first + 1). -
Now we will backtrack, that is,
movies_list[first], movies_list[i] = movies_list[i], movies_list[first]back. ...