XpandNotes

exploring the intersection of technology and creativity

Union and Enumeration

Union A union, like a structure, consists of several members, possibly of different types. The compiler allocates only enough space for the largest of the members, which overlay each other within ...

Posted by blueskyson on February 18, 2020

Structure

Structure Variables Suppose you want to store data of a student, you may store his name, age, height, score… Though an array can store several elements, every element must be the same type! For in...

Posted by blueskyson on February 17, 2020

Array and String

What is an Array An array is a data format that store several value of the same type. For example, an array can store 12 integers indicating day number of every month. Compiler won’t check i...

Posted by blueskyson on February 16, 2020

Variables

Naming Variables C++ encourages user declare meaningful variables. For instance, to express “cost of trip”, the corresponding variable can be named as cost_of_trip or CostOfTrip, instead of cot, x...

Posted by blueskyson on February 16, 2020

C++ Beginning

main() Function 1 2 3 4 5 int main() //function heading { statements return 0; } A function has two parts. One is called function heading. The first word int is call return type, indicati...

Posted by blueskyson on February 16, 2020

Positional Notation

The conversion of positional notation is quite important in computer science since the data are stored as binary signals in disks and memories. We must convert them into decimal so as to make use o...

Posted by blueskyson on February 15, 2020

Two Circles Touch Externally

This post is for solving the intersections of two circles. Suppose the radius of $ C_1 $ is $ r_1 $, and the radius of $ C_2 $ is $ r_2 $. Let $ θ $ be the angel between $ \overline{A C} $ and hor...

Posted by blueskyson on February 14, 2020