Category Archives: Uncategorized

Longest Palindromic Substring

Problem Write a function that, given an input string, locates and returns the longest sequence in the string that is a palindrome. Solution Every sub-string starting from the longest to the shortest needs to checked as shown below is_palindrome can … Continue reading

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On computing the checksum

Problem Marius Bancila [Bancila 2018](Chapter 8, Problem 69) describes a checksum computation problem which can be paraphrased as follows: Let X = x1x2…xN where xi is a decimal digit. X is a valid number if (Σi=0N (N-i+1)*xi) mod 10 = … Continue reading

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Linq for C++

Motivation The benefits of SQL-like declarative syntax for imperative programming languages like C# is [well documented](www.tutorialsteacher.com/linq/why.linq) Linq as it is known in C# has been implemented by more than one team in C++. The main advantages are Improved Readablity Declarative … Continue reading

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A quick note on all permutations

Marius Bancila [Bancila 2018] (Chapter 6, problem 52) poses the next permutation problem as follows: Write a function that, prints on the console all the possible permutations of a given string. and provides a recursive version of the solution as … Continue reading

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Why use Latex over Word

Word is an application that helps layout documents. Latex is a similar application except that it is not a Graphical User Interface (GUI) application like word. It is a notation that must be transformed or compiled from markup text to … Continue reading

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Arithmetic Division: Old wine in new bottle

Given two positive integers A and B compute the quotient and remainder without using multiplication. This is an old problem except, in optimising the algorithm we derive the long division method taught in primary school. Problem: Given A and B, … Continue reading

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Liberty in the Digital Age

The rapid spread of “fake news” and “alternative facts” on the internet is a threat to freedom as such data can be used to manipulate people into doing things that are not in their best interests. In a recent article … Continue reading

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