Algorithms
28 Coding Challenges in 28 Days
28 classic problems to test your knowledge of algorithms and data structures –– with detailed walkthroughs for each of them.
ReadSliding Puzzle
A 2x3 puzzle board has tiles numbered 1 to 5 and an empty square represented by 0. A move consists of swapping 0 with an adjacent number. The puzzle is solved when [[1, 2, 3], [4, 5, 0]] is achieved. Given a puzzle configuration, return the least number of moves required to solve it.
ReadConvex Hull
There are multiple trees growing in a garden, each with a distinct (x, y) coordinate. You are tasked to enclose all of these trees with a single rope. The amount of rope you use should be minimised. Find the coordinates of the trees located along the rope.
ReadHuffman Coding
Given a set of characters and their corresponding frequencies of occurrence, produce Huffman codes for each character such that the average code length is minimised. Return the average code length.
ReadThinking About Partitions
Given an array with n objects colored red, white, or blue, sort them in-place in a single pass. Objects of the same color should be adjacent to each other and the sorted colors should be in the order of red, white, and blue.
ReadQuerying Range Sums (2D)
Design a matrix-like data structure that allows you to update elements and query submatrix sums efficiently.
ReadQuerying Range Sums
Design an array-like data structure that allows you to update elements and query subarray sums efficiently.
ReadLongest Subarray with a Sum Constraint
Given an array of numbers A and a key k, find the length of the longest subarray whose sum is less than or equal to k.
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