Exercise Solution:

1. Write a program to find the factorial of a given number using recursion.

#include <stdio.h>
// Function to calculate factorial using recursion
unsigned long long factorial(int n) {
// Base case: factorial of 0 is 1
if (n == 0)
return 1;
// Recursive case: factorial(n) = n * factorial(n-1)
else
return n * factorial(n - 1);
}

int main() {
int num;
unsigned long long fact;
printf("Enter a positive integer: ");
scanf("%d", &num);
if (num < 0)
printf("Factorial of a negative number is not defined.\n");
else {
fact = factorial(num);
printf("Factorial of %d = %llu\n", num, fact);
}
return 0;
}
2. Write a program to check whether a given number is prime or not.
#include <stdio.h>

// Function to check whether a number is prime or not

int isPrime(int num) {

int i;

// 0 and 1 are not prime numbers

if (num <= 1)
 return 0;

// Check divisibility from 2 to square root of the number

for (i = 2; i * i <= num; i++) {

if (num % i == 0)

return 0; // Not a prime number

return 1; // Prime number

int main() {

int num;

printf("Enter a positive integer: ");

scanf("%d", &num);

// Check if the number is prime or not

if (isPrime(num))

printf("%d is a prime number.\n", num);

else

printf("%d is not a prime number.\n", num);

return 0;

}
 3. Write a program to reverse a given integer number.
#include <stdio.h>

// Function to reverse a given integer number

int reverseNumber(int num) {

int reversed = 0;

// Reversing the digits of the number

while (num != 0) {

int digit = num % 10;

reversed = reversed * 10 + digit;

num /= 10;

return reversed;

int main() {

int num, reversedNum;

printf("Enter an integer: ");

scanf("%d", &num);

// Call function to reverse the number

reversedNum = reverseNumber(num);
 printf("Reversed number: %d\n", reversedNum);

return 0;

4. Write a C program to compute the sum of the digits of a given integer number.
#include <stdio.h>

// Function to compute the sum of digits of a given integer number

int sumOfDigits(int num) {

int sum = 0;

// Compute the sum of digits

while (num != 0) {

sum += num % 10;

num /= 10;

return sum;

int main() {

int num, sum;

printf("Enter an integer: ");

scanf("%d", &num);
 // Call function to compute sum of digits

sum = sumOfDigits(num);

printf("Sum of digits: %d\n", sum);

return 0;

5. Develop a program to print Fibonacci series up to a given number of terms.

#include <stdio.h>

// Function to print Fibonacci series up to n terms

void fibonacciSeries(int n) {
int first = 0, second = 1, next, i;

printf("Fibonacci Series up to %d terms: ", n);

for (i = 1; i <= n; ++i) {

printf("%d, ", first);
next = first + second;
first = second;
second = next;
}
}

int main() {
int numTerms;

printf("Enter the number of terms for Fibonacci series: ");

scanf("%d", &numTerms);

fibonacciSeries(numTerms);

return 0;
}
6. Write a program to find the greatest common divisor (GCD) of two numbers using
Euclid's algorithm.
#include <stdio.h>

// Function to find the greatest common divisor (GCD) using Euclid's algorithm

int gcd(int a, int b) {

int temp;

while (b != 0) {

temp = b;

b = a % b;

a = temp;

return a;

int main() {

int num1, num2;

printf("Enter two integers: ");

scanf("%d %d", &num1, &num2);

// Ensure both numbers are positive

if (num1 < 0 || num2 < 0) {

printf("Please enter positive integers only.\n");

return 1;

}
 // Call function to find GCD

int result = gcd(num1, num2);

printf("Greatest Common Divisor (GCD) of %d and %d is: %d\n", num1, num2, result);

return 0;

7. Write a C program to generate Pascal's triangle up to a specified number of rows.

#include <stdio.h>

// Function to generate Pascal's triangle up to n rows

void generatePascalsTriangle(int n) {
int coef = 1, space, i, j;

printf("Pascal's Triangle up to %d rows:\n", n);

for (i = 0; i < n; i++) {

// Printing spaces for formatting
for (space = 1; space <= n - i; space++)
printf(" ");

for (j = 0; j <= i; j++) {

if (j == 0 || i == 0)
coef = 1;
else
coef = coef * (i - j + 1) / j;

printf("%4d", coef);
}
printf("\n");
}
}

int main() {
int numRows;

printf("Enter the number of rows for Pascal's triangle: ");

 scanf("%d", &numRows);

generatePascalsTriangle(numRows);

return 0;
}
8. Develop a program to compute the sum of series 1/1! + 1/2! + 1/3! + ... + 1/n!

#include <stdio.h>

// Function to calculate factorial

unsigned long long factorial(int n) {
if (n == 0 || n == 1)
return 1;
else
return n * factorial(n - 1);
}

// Function to compute the sum of series

double sumOfSeries(int n) {
double sum = 0;
for (int i = 1; i <= n; i++) {
sum += 1.0 / factorial(i);
}
return sum;
}

int main() {
int n;

printf("Enter the value of n: ");

scanf("%d", &n);

if (n < 0) {
printf("Please enter a non-negative integer.\n");
return 1;
}

double result = sumOfSeries(n);

printf("Sum of the series up to %d terms: %lf\n", n, result);

return 0;
 }
9. Write a program to find the roots of a quadratic equation given the coefficients a, b, and
c.

#include <stdio.h>
#include <math.h>

// Function to find the roots of a quadratic equation

void findRoots(double a, double b, double c) {
double discriminant, root1, root2;

// Calculate discriminant
discriminant = b * b - 4 * a * c;

// Real and distinct roots

if (discriminant > 0) {
root1 = (-b + sqrt(discriminant)) / (2 * a);
root2 = (-b - sqrt(discriminant)) / (2 * a);
printf("Roots are real and distinct:\n");
printf("Root 1 = %.2lf\n", root1);
printf("Root 2 = %.2lf\n", root2);
}
// Real and equal roots
else if (discriminant == 0) {
root1 = root2 = -b / (2 * a);
printf("Roots are real and equal:\n");
printf("Root 1 = Root 2 = %.2lf\n", root1);
}
// Imaginary roots
else {
double realPart = -b / (2 * a);
double imaginaryPart = sqrt(-discriminant) / (2 * a);
printf("Roots are complex and imaginary:\n");
printf("Root 1 = %.2lf + %.2lfi\n", realPart, imaginaryPart);
printf("Root 2 = %.2lf - %.2lfi\n", realPart, imaginaryPart);
}
}

int main() {
double a, b, c;

printf("Enter coefficients a, b, and c of the quadratic equation (ax^2 + bx + c): ");

scanf("%lf %lf %lf", &a, &b, &c);
 if (a == 0) {
printf("The coefficient 'a' must not be zero for a quadratic equation.\n");
return 1;
}

findRoots(a, b, c);

return 0;
}
10. Write a program to sort an array of integers in ascending order using bubble sort.
#include <stdio.h>

// Function to perform bubble sort

void bubbleSort(int array[], int size) {

int i, j, temp;

for (i = 0; i < size - 1; i++) {

// Last i elements are already in place

for (j = 0; j < size - i - 1; j++) {

// Swap adjacent elements if they are in the wrong order

if (array[j] > array[j + 1]) {

temp = array[j];

array[j] = array[j + 1];

array[j + 1] = temp;

}
int main() {

int array[] = {64, 34, 25, 12, 22, 11, 90};

int size = sizeof(array) / sizeof(array[0]);

int i;

printf("Array before sorting:\n");

for (i = 0; i < size; i++) {

printf("%d ", array[i]);

printf("\n");

// Call bubble sort function

bubbleSort(array, size);

printf("Array after sorting in ascending order:\n");

for (i = 0; i < size; i++) {

printf("%d ", array[i]);

printf("\n");

return 0;

11. Write a program to implement a basic calculator that can perform addition, subtraction,
multiplication, and division operations on two numbers.
#include <stdio.h>
int main() {

char operator;

double num1, num2, result;

printf("Enter an operator (+, -, *, /): ");

scanf(" %c", &operator);

printf("Enter two numbers: ");

scanf("%lf %lf", &num1, &num2);

switch (operator) {

case '+':

result = num1 + num2;

printf("Result: %.2lf + %.2lf = %.2lf\n", num1, num2, result);

break;

case '-':

result = num1 - num2;

printf("Result: %.2lf - %.2lf = %.2lf\n", num1, num2, result);

break;

case '*':

result = num1 * num2;

printf("Result: %.2lf * %.2lf = %.2lf\n", num1, num2, result);

break;

case '/':
 if (num2 == 0) {

printf("Error! Division by zero is not allowed.\n");

} else {

result = num1 / num2;

printf("Result: %.2lf / %.2lf = %.2lf\n", num1, num2, result);

break;

default:

printf("Invalid operator!\n");

return 0;

12. Write a C program to convert a given decimal number to binary, octal, and hexadecimal
formats.
#include <stdio.h>

// Function to convert decimal to binary

void decimalToBinary(int num) {

int binary[32], i = 0;

// Convert decimal to binary

while (num > 0) {

binary[i] = num % 2;

num /= 2;

i++;
 }

printf("Binary equivalent: ");

// Print binary in reverse order

for (int j = i - 1; j >= 0; j--) {

printf("%d", binary[j]);

printf("\n");

// Function to convert decimal to octal

void decimalToOctal(int num) {

int octal[32], i = 0;

// Convert decimal to octal

while (num > 0) {

octal[i] = num % 8;

num /= 8;

i++;

printf("Octal equivalent: ");

// Print octal in reverse order

for (int j = i - 1; j >= 0; j--) {

printf("%d", octal[j]);
 }

printf("\n");

// Function to convert decimal to hexadecimal

void decimalToHexadecimal(int num) {

char hexadecimal[32];

int i = 0, remainder;

// Convert decimal to hexadecimal

while (num > 0) {

remainder = num % 16;

if (remainder < 10)

hexadecimal[i] = remainder + '0';

else

hexadecimal[i] = remainder + 'A' - 10;

num /= 16;

i++;

printf("Hexadecimal equivalent: ");

// Print hexadecimal in reverse order

for (int j = i - 1; j >= 0; j--) {

printf("%c", hexadecimal[j]);

}
 printf("\n");

int main() {

int num;

printf("Enter a decimal number: ");

scanf("%d", &num);

if (num < 0) {

printf("Please enter a non-negative integer.\n");

return 1;

decimalToBinary(num);

decimalToOctal(num);

decimalToHexadecimal(num);

return 0;

13. Write a program to count the occurrences of a specific character in a given string.
#include <stdio.h>

// Function to count occurrences of a specific character in a string

int countOccurrences(char *str, char ch) {

 int count = 0;

// Iterate through the string

while (*str != '\0') {

// If the current character matches the specified character, increment count

if (*str == ch)

count++;

str++;

return count;

int main() {

char str[100];

char ch;

printf("Enter a string: ");

fgets(str, sizeof(str), stdin);

printf("Enter the character to count occurrences: ");

scanf("%c", &ch);

// Call function to count occurrences

int occurrences = countOccurrences(str, ch);

 printf("Occurrences of '%c' in the string: %d\n", ch, occurrences);

return 0;

14. Write a program to check whether a given string is a palindrome or not.

#include <stdio.h>

#include <string.h>

#include <ctype.h>

// Function to check if a string is a palindrome

int isPalindrome(char *str) {

int i, j;

int length = strlen(str);

// Convert the string to lowercase

for (i = 0; i < length; i++) {

str[i] = tolower(str[i]);

// Check if the string is a palindrome

for (i = 0, j = length - 1; i < j; i++, j--) {

// Skip non-alphanumeric characters

while (!isalnum(str[i]) && i < j) {

i++;
 }

while (!isalnum(str[j]) && i < j) {

j--;

if (str[i] != str[j]) {

return 0; // Not a palindrome

return 1; // Palindrome

int main() {

char str[100];

printf("Enter a string: ");

fgets(str, sizeof(str), stdin);

// Remove newline character from fgets

if (str[strlen(str) - 1] == '\n') {

str[strlen(str) - 1] = '\0';

// Check if the string is a palindrome

if (isPalindrome(str)) {

printf("The string is a palindrome.\n");

 } else {

printf("The string is not a palindrome.\n");

return 0;

15. Write a program that use for and while loop to store 10 elements in a single dimensional
array in C programming and display the result.
#include <stdio.h>

int main() {

int array[10];

int i = 0;

// Using a for loop to store elements in the array

printf("Enter 10 elements:\n");

for (i = 0; i < 10; i++) {

printf("Enter element %d: ", i + 1);

scanf("%d", &array[i]);

// Displaying the elements using a while loop

printf("Elements stored in the array:\n");

i = 0;

while (i < 10) {

printf("%d ", array[i]);

 i++;

printf("\n");

return 0;

16. Write a program to Store 10 alphabets in a character type array and display them
sequentially.

#include <stdio.h>

int main() {

char alphabets[10];

int i;

// Storing 10 alphabets in the array

printf("Enter 10 alphabets:\n");

for (i = 0; i < 10; i++) {

printf("Enter alphabet %d: ", i + 1);

scanf(" %c", &alphabets[i]); // Note the space before %c to consume the newline character

// Displaying the alphabets sequentially

printf("Alphabets stored in the array:\n");

for (i = 0; i < 10; i++) {

printf("%c ", alphabets[i]);

 }

printf("\n");

return 0;

17. Write a program to find the largest and smallest elements in an array.
#include <stdio.h>

int main() {

int array[100], size, i;

int smallest, largest;

printf("Enter the number of elements in the array: ");

scanf("%d", &size);

// Input array elements

printf("Enter %d elements:\n", size);

for (i = 0; i < size; i++) {

printf("Enter element %d: ", i + 1);

scanf("%d", &array[i]);

// Assume the first element as the smallest and largest initially

smallest = largest = array[0];

 // Finding the smallest and largest elements in the array

for (i = 1; i < size; i++) {

if (array[i] < smallest)

smallest = array[i];

if (array[i] > largest)

largest = array[i];

// Display the smallest and largest elements

printf("Smallest element in the array: %d\n", smallest);

printf("Largest element in the array: %d\n", largest);

return 0;

18. Write a program to create two dimensional array of 2x3 size, take integer input and
display them in matrix form.
#include <stdio.h>

int main() {

int matrix[2][3]; // 2x3 matrix

int i, j;

// Input elements into the matrix

printf("Enter elements for a 2x3 matrix:\n");

for (i = 0; i < 2; i++) {

for (j = 0; j < 3; j++) {

 printf("Enter element at position (%d, %d): ", i + 1, j + 1);

scanf("%d", &matrix[i][j]);

// Display the matrix

printf("Matrix form:\n");

for (i = 0; i < 2; i++) {

for (j = 0; j < 3; j++) {

printf("%d ", matrix[i][j]);

printf("\n");

return 0;

19. Write a program to find the addition of 2x2 matrix and display their result.

#include <stdio.h>

int main() {

int matrix1[2][2], matrix2[2][2], result[2][2];

int i, j;

// Input elements for first matrix

printf("Enter elements for the first 2x2 matrix:\n");

for (i = 0; i < 2; i++) {

for (j = 0; j < 2; j++) {

printf("Enter element at position (%d, %d): ", i + 1, j + 1);

scanf("%d", &matrix1[i][j]);

// Input elements for second matrix

printf("Enter elements for the second 2x2 matrix:\n");

for (i = 0; i < 2; i++) {

for (j = 0; j < 2; j++) {

printf("Enter element at position (%d, %d): ", i + 1, j + 1);

scanf("%d", &matrix2[i][j]);

// Perform matrix addition

for (i = 0; i < 2; i++) {

for (j = 0; j < 2; j++) {

result[i][j] = matrix1[i][j] + matrix2[i][j];

// Display the result matrix

 printf("Result of matrix addition:\n");

for (i = 0; i < 2; i++) {

for (j = 0; j < 2; j++) {

printf("%d ", result[i][j]);

printf("\n");

return 0;

20. Use structure to store the basic information of a student and display them on screen.
#include <stdio.h>

// Define a structure to store student information

struct Student {

char name[50];

int age;

long int rollNumber;

float marks;

};

int main() {

// Declare a variable of type struct Student

struct Student student;

 // Input student information

printf("Enter student information:\n");

printf("Name: ");

scanf("%s", student.name); // Assuming name doesn't contain spaces

printf("Age: ");

scanf("%d", &student.age);

printf("Roll Number: ");

scanf("%ld", &student.rollNumber);

printf("Marks: ");

scanf("%f", &student.marks);

// Display student information

printf("\nStudent Information:\n");

printf("Name: %s\n", student.name);

printf("Age: %d\n", student.age);

printf("Roll Number: %ld\n", student.rollNumber);

printf("Marks: %.2f\n", student.marks);

return 0;

21. Write a program to perform basic file operations like reading from a file, writing to a file,
and copying files.
#include <stdio.h>

#include <stdlib.h>

#define MAX_FILENAME_LENGTH 100

#define BUFFER_SIZE 1024

// Function to read content from a file and display it

void readFile(char *filename) {

FILE *file = fopen(filename, "r");

if (file == NULL) {

printf("Error opening file for reading.\n");

return;

char buffer[BUFFER_SIZE];

printf("Contents of the file '%s':\n", filename);

while (fgets(buffer, BUFFER_SIZE, file) != NULL) {

printf("%s", buffer);

fclose(file);

// Function to write content to a file

void writeFile(char *filename, char *content) {

FILE *file = fopen(filename, "w");

if (file == NULL) {

printf("Error opening file for writing.\n");

return;
 }

fputs(content, file);

printf("Content successfully written to the file '%s'.\n", filename);

fclose(file);

// Function to copy content from one file to another

void copyFile(char *sourceFilename, char *destinationFilename) {

FILE *sourceFile = fopen(sourceFilename, "r");

if (sourceFile == NULL) {

printf("Error opening source file for reading.\n");

return;

FILE *destinationFile = fopen(destinationFilename, "w");

if (destinationFile == NULL) {

printf("Error opening destination file for writing.\n");

fclose(sourceFile);

return;

char buffer[BUFFER_SIZE];
 size_t bytesRead;

while ((bytesRead = fread(buffer, 1, BUFFER_SIZE, sourceFile)) > 0) {

fwrite(buffer, 1, bytesRead, destinationFile);

printf("File '%s' successfully copied to '%s'.\n", sourceFilename, destinationFilename);

fclose(sourceFile);

fclose(destinationFile);

int main() {

char sourceFilename[MAX_FILENAME_LENGTH];

char destinationFilename[MAX_FILENAME_LENGTH];

char content[BUFFER_SIZE];

printf("Enter the name of the source file: ");

scanf("%s", sourceFilename);

printf("Enter the name of the destination file: ");

scanf("%s", destinationFilename);

printf("Enter content to write to the destination file:\n");

getchar(); // Consume the newline character left in the input buffer

fgets(content, BUFFER_SIZE, stdin);

 readFile(sourceFilename);

writeFile(destinationFilename, content);

copyFile(sourceFilename, "copy_of_file.txt");

return 0;

22. Write a program to implement structure and file handling in C to store information of 10
employees of a school and print them in proper format.
#include <stdio.h>

#include <stdlib.h>

#define MAX_NAME_LENGTH 50

// Define a structure to store employee information

struct Employee {

char name[MAX_NAME_LENGTH];

int age;

long int employeeID;

float salary;

};

// Function to input employee information

void inputEmployee(struct Employee *employee) {

printf("Enter employee name: ");

scanf("%s", employee->name);
 printf("Enter employee age: ");

scanf("%d", &employee->age);

printf("Enter employee ID: ");

scanf("%ld", &employee->employeeID);

printf("Enter employee salary: ");

scanf("%f", &employee->salary);

// Function to print employee information

void printEmployee(struct Employee employee) {

printf("Employee Name: %s\n", employee.name);

printf("Employee Age: %d\n", employee.age);

printf("Employee ID: %ld\n", employee.employeeID);

printf("Employee Salary: %.2f\n", employee.salary);

int main() {

// Declare an array of 10 Employee structures

struct Employee employees[10];

// Input information for 10 employees

printf("Enter information for 10 employees:\n");

for (int i = 0; i < 10; i++) {

printf("Enter details for Employee %d:\n", i + 1);

inputEmployee(&employees[i]);
}

// Open a file for writing

FILE *file = fopen("employee_info.txt", "w");

if (file == NULL) {

printf("Error opening file for writing.\n");

return 1;

// Write employee information to the file

fprintf(file, "Employee Information:\n");

for (int i = 0; i < 10; i++) {

fprintf(file, "Employee %d:\n", i + 1);

fprintf(file, "Name: %s\n", employees[i].name);

fprintf(file, "Age: %d\n", employees[i].age);

fprintf(file, "ID: %ld\n", employees[i].employeeID);

fprintf(file, "Salary: %.2f\n", employees[i].salary);

fprintf(file, "\n");

// Close the file

fclose(file);

// Print employee information from the array

printf("\nEmployee Information:\n");
 for (int i = 0; i < 10; i++) {

printf("Employee %d:\n", i + 1);

printEmployee(employees[i]);

printf("\n");

printf("Employee information has been saved to 'employee_info.txt'.\n");

return 0;

23. Write a program to perform subtraction, multiplication, and transpose operations.

#include <stdio.h>

#define ROWS 3

#define COLS 3

// Function to perform subtraction of two matrices

void subtractMatrices(int mat1[][COLS], int mat2[][COLS], int result[][COLS]) {

for (int i = 0; i < ROWS; i++) {

for (int j = 0; j < COLS; j++) {

result[i][j] = mat1[i][j] - mat2[i][j];

}
// Function to perform multiplication of two matrices

void multiplyMatrices(int mat1[][COLS], int mat2[][COLS], int result[][COLS]) {

for (int i = 0; i < ROWS; i++) {

for (int j = 0; j < COLS; j++) {

result[i][j] = 0;

for (int k = 0; k < COLS; k++) {

result[i][j] += mat1[i][k] * mat2[k][j];

// Function to calculate transpose of a matrix

void transposeMatrix(int mat[][COLS], int transpose[][ROWS]) {

for (int i = 0; i < ROWS; i++) {

for (int j = 0; j < COLS; j++) {

transpose[j][i] = mat[i][j];

// Function to display a matrix

void displayMatrix(int mat[][COLS]) {

for (int i = 0; i < ROWS; i++) {

for (int j = 0; j < COLS; j++) {

 printf("%d ", mat[i][j]);

printf("\n");

printf("\n");

int main() {

int matrix1[ROWS][COLS] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

int matrix2[ROWS][COLS] = {{9, 8, 7}, {6, 5, 4}, {3, 2, 1}};

int result[ROWS][COLS];

int transpose[COLS][ROWS];

// Subtract matrices

subtractMatrices(matrix1, matrix2, result);

printf("Subtraction Result:\n");

displayMatrix(result);

// Multiply matrices

multiplyMatrices(matrix1, matrix2, result);

printf("Multiplication Result:\n");

displayMatrix(result);

// Transpose matrix

transposeMatrix(matrix1, transpose);
 printf("Transpose of Matrix 1:\n");

displayMatrix(transpose);

return 0;

}
a. Write a C program to find the factorial of a number by using function
#include <stdio.h>
// Function to calculate factorial
int factorial(int n) {
if (n == 0 || n == 1)
return 1;
else
return n * factorial(n - 1);
}
int main() {
int num;
printf("Enter a number: ");
scanf("%d", &num);
printf("Factorial of %d is %d\n", num, factorial(num));
return 0;
}

b. Write a C program to check whether a given number is a prime number or not by using
functions.
#include <stdio.h>
#include <stdbool.h>
// Function to check prime number
bool isPrime(int n) {
if (n <= 1)
return false;
for (int i = 2; i * i <= n; i++) {
if (n % i == 0)
return false;
}
return true;
}
int main() {
int num;
printf("Enter a number: ");
scanf("%d", &num);
if (isPrime(num))
printf("%d is a prime number\n", num);
else
printf("%d is not a prime number\n", num);
 return 0;
}

c. Write a C program to find the sum of digits of a number.

#include <stdio.h>
// Function to compute sum of digits
int sumOfDigits(int n) {
int sum = 0;
while (n != 0) {
sum += n % 10;
n /= 10;
}
return sum;
}
int main() {
int num;
printf("Enter a number: ");
scanf("%d", &num);
printf("Sum of digits of %d is %d\n", num, sumOfDigits(num));
return 0;
}

d. Write a C program to find the Fibonacci number up to given terms by using functions
#include <stdio.h>

// Function to print Fibonacci series

void fibonacci(int n) {
int a = 0, b = 1, c;
printf("Fibonacci Series up to %d terms: ", n);
printf("%d %d ", a, b);
for (int i = 3; i <= n; i++) {
c = a + b;
printf("%d ", c);
a = b;
b = c;
}
printf("\n");
}
 int main() {
int num;
printf("Enter the number of terms: ");
scanf("%d", &num);
fibonacci(num);
return 0;
}

e. Write a C program to calculate exponent or power of a given number by using function.

#include <stdio.h>

// Function to calculate power

double power(double base, int exponent) {
if (exponent == 0)
return 1;
else if (exponent > 0)
return base * power(base, exponent - 1);
else
return (1 / base) * power(base, exponent + 1);
}

int main() {
double base;
int exponent;
printf("Enter base: ");
scanf("%lf", &base);
printf("Enter exponent: ");
scanf("%d", &exponent);
printf("%.2lf raised to the power %d is %.2lf\n", base, exponent, power(base,
exponent));
return 0;
}

f. Write a C program that generates the Fibonacci series up to a given number using recursion
function.
#include <stdio.h>

int fibonacci(int n) {
 if (n <= 1)
return n;
return fibonacci(n - 1) + fibonacci(n - 2);
}

int main() {
int n, i;
printf("Enter the number of terms: ");
scanf("%d", &n);
printf("Fibonacci series: ");
for (i = 0; i < n; i++) {
printf("%d ", fibonacci(i));
}
return 0;
}

g. Write a C program that calculates the factorial of a given number using recursion
function.
#include <stdio.h>

int factorial(int n) {
if (n == 0)
return 1;
return n * factorial(n - 1);
}

int main() {
int n;
printf("Enter a non-negative integer: ");
scanf("%d", &n);
if (n < 0) {
printf("Error: Factorial is not defined for negative numbers.\n");
} else {
printf("Factorial of %d = %d\n", n, factorial(n));
}
return 0;
}