C Programming Code Examples
C > Linked Lists Code Examples
Find Number of Occurrences of All Elements in a Linked List
/* Find Number of Occurrences of All Elements in a Linked List */
#include <stdio.h>
#include <stdlib.h>
struct node
{
int j;
struct node *next;
};
struct node_occur
{
int j;
int times;
struct node_occur *next;
};
void create(struct node **);
void occur(struct node *, struct node_occur **);
void release(struct node **);
void release_2(struct node_occur **);
void display(struct node *);
void disp_occur(struct node_occur *);
int main()
{
struct node *p = NULL;
struct node_occur *head = NULL;
int n;
printf("Enter data into the list\n");
create(&p);
printf("Displaying the occurence of each node in the list:\n");
display(p);
occur(p, &head);
disp_occur(head);
release(&p);
release_2(&head);
return 0;
}
void occur(struct node *head, struct node_occur **result)
{
struct node *p;
struct node_occur *temp, *prev;
p = head;
while (p != NULL)
{
temp = *result;
while (temp != NULL && temp->j != p->j)
{
prev = temp;
temp = temp->next;
}
if (temp == NULL)
{
temp = (struct node_occur *)malloc(sizeof(struct node_occur));
temp->j = p->j;
temp->times = 1;
temp->next = NULL;
if (*result != NULL)
{
prev->next = temp;
}
else
{
*result = temp;
}
}
else
{
temp->times += 1;
}
p = p->next;
}
}
void create(struct node **head)
{
int c, ch;
struct node *temp, *rear;
do
{
printf("Enter number: ");
scanf("%d", &c);
temp = (struct node *)malloc(sizeof(struct node));
temp->j = c;
temp->next = NULL;
if (*head == NULL)
{
*head = temp;
}
else
{
rear->next = temp;
}
rear = temp;
printf("Do you wish to continue [1/0]: ");
scanf("%d", &ch);
} while (ch != 0);
printf("\n");
}
void display(struct node *p)
{
while (p != NULL)
{
printf("%d\t", p->j);
p = p->next;
}
printf("\n");
}
void disp_occur(struct node_occur *p)
{
printf("****************\n Number\tOccurence\n**************\n");
while (p != NULL)
{
printf(" %d\t\t%d\n", p->j, p->times);
p = p->next;
}
}
void release(struct node **head)
{
struct node *temp = *head;
*head = (*head)->next;
while ((*head) != NULL)
{
free(temp);
temp = *head;
(*head) = (*head)->next;
}
}
void release_2(struct node_occur **head)
{
struct node_occur *temp = *head;
*head = (*head)->next;
while ((*head) != NULL)
{
free(temp);
temp = *head;
(*head) = (*head)->next;
}
}
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.
An expression containing logical operator returns either 0 or 1 depending upon whether expression results true or false. Logical operators are commonly used in decision making in C programming. These operators are used to perform logical operations and used with conditional statements like C if-else statements.
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.
#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:
The if-else statement is used to perform two operations for a single condition. The if-else statement is an extension to the if statement using which, we can perform two different operations, i.e., one is for the correctness of that condition, and the other is for the incorrectness of the condition. Here, we must notice that if and else block cannot be executed simiulteneously. Using if-else statement is always preferable since it always invokes an otherwise case with every if condition.
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,
The sizeof() operator is commonly used in C. It determines the size of the expression or the data type specified in the number of char-sized storage units. The sizeof() operator contains a single operand which can be either an expression or a data typecast where the cast is data type enclosed within parenthesis. The data type cannot only be primitive data types such as integer or floating data types, but it can also be pointer data types and compound data types such as unions and structs.
Allocate memory block. Allocates a block of size bytes of memory, returning a pointer to the beginning of the block. The content of the newly allocated block of memory is not initialized, remaining with indeterminate values. If size is zero, the return value depends on the particular library implementation (it may or may not be a null pointer), but the returned pointer shall not be dereferenced. The "malloc" or "memory allocation" method in C is used to dynamically allocate a single large block of memory with the specified size. It returns a pointer of type void which can be cast into a pointer of any form. It doesn't Iniatialize memory at execution time so that it has initializes each block with the default garbage value initially.
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.
While loop is also known as a pre-tested loop. In general, a while loop allows a part of the code to be executed multiple times depending upon a given boolean condition. It can be viewed as a repeating if statement. The while loop is mostly used in the case where the number of iterations is not known in advance. The while loop evaluates the test expression inside the parentheses (). If test expression is true, statements inside the body of while loop are executed. Then, test expression is evaluated again. The process goes on until test expression is evaluated to false. If test expression is false, the loop terminates.
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.
The free() function in C library allows you to release or deallocate the memory blocks which are previously allocated by calloc(), malloc() or realloc() functions. It frees up the memory blocks and returns the memory to heap. It helps freeing the memory in your program which will be available for later use. In C, the memory for variables is automatically deallocated at compile time. For dynamic memory allocation in C, you have to deallocate the memory explicitly. If not done, you may encounter out of memory error.
C program code find the sum of odd and even numbers from 1 to N. Take Number N upto which we have to find the sum as input. Using for loop take the elements one by one from 1
Program to Fibonacci Series. Fibonacci Series generates subsequent number by adding two previous numbers and Fibonacci Series starts from 2 numbers F0 & F1. The initial values of
File I/O for Binary files in C. Pointers for both binary files. Open for binary2.exe file in rb mode. Test logic for successful open. Open file binary2.exe in "wb" mode for writing and
C program to evaluate a given polynomial by reading its coefficients in an array. Formula is P(x)=AnXn + An-1Xn-1 + An-2Xn-2+... +A1X + A0. The 'polynomial' can be written as: P(x) =
