#design

Solutions This problem can be solved in several ways, each carrying its own pros, cons and tradeoffs. All the solutions are based on this observation: the answer is always \(max(6-n,4-d)\) where \(n\) is string length and \(d\) is the number of different type of characters that are already present in the input password. Preamble We call character family the group of characters belonging to the same requirement. The problem requires to check against 4: digits, lowercase letters, uppercase letters, special chars. [Read More]

Solutions The simplest solution to this problem involves storing a copy of the entire array every time a new version is saved. This way, to retrieve the value of an element at a specific version, we can simply access the saved array for that version. However, while easy to understand, this approach is highly inefficient for large arrays or when versions are taken frequently. If there are \(N\) calls to each function, this method would store \(N\) full copies of the array, leading to significant memory usage and poor time performance. [Read More]