# C Programming Code Examples

## C > Games and Graphics Code Examples

### Program to Solve the Magic Squares Puzzle without using Recursion

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/* Program to Solve the Magic Squares Puzzle without using Recursion The following C program, using iteration, finds the magic square for a given odd sized number. A magic square is an arrangement of numbers from 1 to n^2 in an [n x n] matrix, with each number occurring exactly once, and such that the sum of the entries of any row, any column, or any main diagonal is the same. */ #include <stdio.h> void magicsq(int, int [][10]); int main( ) { int size; int a[10][10]; printf("Enter the size: "); scanf("%d", &size); if (size % 2 == 0) { printf("Magic square works for an odd numbered size\n"); } else { magicsq(size, a); } return 0; } void magicsq(int size, int a[][10]) { int sqr = size * size; int x = 0, y = size / 2, k; for (k = 1; k <= sqr; ++k) { a[x][y] = k; x--; y++; if (k % size == 0) { x += 2; --y; } else { if (y == size) { y -= size; } else if (x < 0) { x += size; } } } for (x = 0; x < size; x++) { for (y = 0; y < size; y++) { printf("%d ", a[x][y]); } printf("\n"); } printf("\n"); }

C supports nesting of loops in C. Nesting of loops is the feature in C that allows the looping of statements inside another loop. Any number of loops can be defined inside another loop, i.e., there is no restriction for defining any number of loops. The nesting level can be defined at n times. You can define any type of loop inside another loop; for example, you can define 'while' loop inside a 'for' loop.

An array is a collection of data items, all of the same type, accessed using a common name. A one-dimensional array is like a list; A two dimensional array is like a table; The C language places no limits on the number of dimensions in an array, though specific implementations may. Some texts refer to one-dimensional arrays as vectors, two-dimensional arrays as matrices, and use the general term arrays when the number of dimensions is unspecified or unimportant.

In C, the "main" function is treated the same as every function, it has a return type (and in some cases accepts inputs via parameters). The only difference is that the main function is "called" by the operating system when the user runs the program. Thus the main function is always the first code executed when a program starts. main() function is a user defined, body of the function is defined by the programmer or we can say main() is programmer/user implemented function, whose prototype is predefined in the compiler. Hence we can say that main() in c programming is user defined as well as predefined because it's prototype is predefined. main() is a system (compiler) declared function whose defined by the user, which is invoked automatically by the operating system when program is being executed.

Read formatted data from stdin. Reads data from stdin and stores them according to the parameter format into the locations pointed by the additional arguments. The additional arguments should point to already allocated objects of the type specified by their corresponding format specifier within the format string. In C programming, scanf() is one of the commonly used function to take input from the user. The scanf() function reads formatted input from the standard input such as keyboards. The scanf() function enables the programmer to accept formatted inputs to the application or production code. Moreover, by using this function, the users can provide dynamic input values to the application.

Writes the C string pointed by format to the standard output (stdout). If format includes format specifiers (subsequences beginning with %), the additional arguments following format are formatted and inserted in the resulting string replacing their respective specifiers. printf format string refers to a control parameter used by a class of functions in the input/output libraries of C programming language. The string is written in a simple template language: characters are usually copied literally into the function's output, but format specifiers, which start with a % character, indicate the location and method to translate a piece of data (such as a number) to characters. "printf" is the name of one of the main C output functions, and stands for "print formatted". printf format strings are complementary to scanf format strings, which provide formatted input (parsing). In both cases these provide simple functionality and fixed format compared to more sophisticated and flexible template engines or parsers,

#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program. Here are the two types of file that can be included using #include:

Assignment operators are used to assign the value, variable and function to another variable. Assignment operators in C are some of the C Programming Operator, which are useful to assign the values to the declared variables. Let's discuss the various types of the assignment operators such as =, +=, -=, /=, *= and %=. The following table lists the assignment operators supported by the C language: Simple assignment operator. Assigns values from right side operands to left side operand. Add AND assignment operator. It adds the right operand to the left operand and assign the result to the left operand.

The for loop is used in the case where we need to execute some part of the code until the given condition is satisfied. The for loop is also called as a per-tested loop. It is better to use for loop if the number of iteration is known in advance. The for-loop statement is a very specialized while loop, which increases the readability of a program. It is frequently used to traverse the data structures like the array and linked list.

The if...else statement executes two different codes depending upon whether the test expression is true or false. Sometimes, a choice has to be made from more than 2 possibilities. The if...else ladder allows you to check between multiple test expressions and execute different statements. In C/C++ if-else-if ladder helps user decide from among multiple options. The C/C++ if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the C else-if ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.

C program to input a number from user and print it into words using for loop. The above logic is correct however it print the words in reverse order. For example, suppose number

Don't U know that there is no month greater than 12. Enter valid month Once again enter the Date Month Year. Fool, Invalid date in February of non leap year. The maximum...

When using while or do-while loop you need to place an increment, decrement statement just above the continue so that counter value is changed for the next iteration. if we do not

1. It is initializing two variables. Note: both are separated by comma (,). 2. It has two test conditions joined together using AND (&&) logical operator. You cannot use multiple test