Web Development

3 Security Must-Knows for Front-End Developers

A brief review of HTTPS, XSS (Cross-Site Scripting), and CSRF (Cross-Site Request Forgery).

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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.

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Algorithms

Sliding 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.

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Algorithms

Convex 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.

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Algorithms

Huffman 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.

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Algorithms

Thinking 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.

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Algorithms

Querying Range Sums (2D)

Design a matrix-like data structure that allows you to update elements and query submatrix sums efficiently.

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Algorithms

Querying Range Sums

Design an array-like data structure that allows you to update elements and query subarray sums efficiently.

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