A Grid of Random Stars, Part II

To count all possible rectangles in a random grid requires a lot of scanning. My first thought was that the process would involve recursion. I wasn’t 100 percent certain, but I wanted to prep the code for such a possibility.

Analyzing a Grid of Random Stars

Ever since I was a little boy and coded my first nested loop, I’ve enjoyed messing with grids in C. I’ve done monthly calendars in grids, rotated grids, manipulated grids mathematically — all sorts of fun girddy stuff. But I’m not done yet.

Messing with Array Subscripts

Array notation involves the array’s name followed by a set of square brackets. Within these brackets is a reference to the array element’s number. It’s important to remember that the first element is zero. But the subscript need not always be a constant integer.

Calculating the Standard Deviation – Solution

The challenge for this month’s Exercise is to calculate the standard deviation for a given set of data points. It’s a “whole population calculation” because all the data points are present. The trick is to follow the equation, transforming it from cryptic math mumbo-jumbo into C code.

Tending Toward Obfuscation

I’m always mindful of the beginner when I write code for this blog. Even with my own code, I often go to pains to write things “the long way” just because I’m in the habit. Not every coder is so thoughtful. The reason is that C tends toward obfuscation. We must revel in this capability.

Calculating the Standard Deviation

Difficulty: ★ ★ ☆ ☆

Even when statistics has barely brushed by you on the subway, you probably know the term standard deviation. It refers to how data is distributed in a group, their distance from the mean. You can use your C programming kung fu to code the standard deviation of a data set, which is the challenge for this month’s Exercise.

From Void to Integer

You can’t just slap a data type upon a variable declared as void. No, a void type can be assigned a pointer. But even then, you can’t just typecast that pointer as an int and get away with it.

Out of the void

The four standard data types in C programming are char, int, float, and double. A fifth type is void, which is used to declare storage of an unknown type. My goal is to see how badly I can abuse this data type.