Design a data structure that acts as a Least Recently Used (LRU) cache. Implement methods to get and put key-value pairs, evicting the least recently used entry when the cache is full.

Given a grid representing land and water, count the number of distinct islands. An island is formed by connected land cells.

Determine if a string can be rotated to match another string. You're essentially checking if one string is a shifted version of the other.

Find the smallest subarray within a given array that has the same degree as the entire array. The degree is defined as the highest frequency of any element.

The problem requires you to flatten a deeply nested array into a single-level array. You need to handle arrays containing other arrays at various levels of nesting.

You are given a collection of intervals. Merge all overlapping intervals into a single interval and return the result.

You are given k sorted lists. Combine all of their elements into a single sorted list and return it.

Compress a given string by replacing consecutive repeating characters with the character followed by the count of repetitions. If the compressed string isn't shorter, return the original.

Imagine a city grid of buildings. Find the maximum total height increase you can make to the buildings while maintaining the original skyline from all four sides.