Tag Archives: algorithms

Solution: The 40 pound stone puzzle

  This is the solution to The 40 pound stone puzzle. If you haven’t read the puzzle yet, click here before you read the solution. This puzzle similar to some of the puzzles in my book Interview Puzzles Dissected. The … Continue reading

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Use digits of Pi to draw a picture in C#

The article 10 stunning images show the beauty hidden in pi shows several ways to use Pi to generate pictures. This example demonstrates one of them. The program starts drawing at the origin (0, 0). It then scans through the … Continue reading

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Look for dates in the digits of Pi in C#

The example Find patterns within pi in C# looks for patterns within the digits of Pi. You can use that example to look for dates such as 4/1. This example determines whether the first 100 thousand digits of Pi contains … Continue reading

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Find patterns within Pi in C#

March 14 is known as Pi Day because its numeric representation 3/14 includes the first three digits of Pi: 3.14. (At least in the United States. In Europe where they usually write dates month first, Pi Day is July 22 … Continue reading

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Puzzle: The 40 pound stone

This is a variation of a puzzle given on Car Talk. It’s similar to some of the puzzles in my book Interview Puzzles Dissected. A farmer uses a double-pan balance and a 40 pound stone to measure 40 pound weights: … Continue reading

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Use an improved extension method to calculate standard deviation in C#

The example Calculate standard deviation in C# makes an extension method that calculates standard deviation for an IEnumerable of integers. Unfortunately because that example works with integers, it cannot work with other data types. Rian Meier showed me this method, … Continue reading

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Make a hangman game in C#

Special thanks to Jeff Scarterfield for the skeleton drawing used by the program. This example builds a simple hangman game that uses the dictionary created by the example Use LINQ to select words of certain lengths from a file in … Continue reading

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Use LINQ to select words of certain lengths from a file in C#

This example uses LINQ to read a file, remove unwanted characters, select words of a specified length, and save the result in a new file. Recently I needed a big word list so I searched around for public domain dictionaries. … Continue reading

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Draw a golden spiral in C#

This example shows how to draw a golden spiral (or phi spiral) in C#. The example Draw a nested series of golden rectangles in C# draws nested rectangles and connects their corners to make a square “spiral.” This example makes … Continue reading

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Draw a nested series of golden rectangles in C#

This program draws golden rectangles, rectangles whose side ratio is equal to φ. For information on φ, see Examine the relationship between the Fibonacci sequence and phi in C#. The program first draws a golden rectangle. It then removes the … Continue reading

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