Program 20 - CSU1128 - CSE 2026 - Shoolini University

Program to print the fibonacci series till an entered number. Fibonacci series is a series where the number at any point is the sum of previous two numbers. Example 9 = 1 2 3 5 8

Explanation

The program prints the Fibonacci series up to a number entered by the user.

Header

The code begins with including the standard input-output header file using #include <stdio.h>.

Variable Declaration

The main() function is defined, and four integer variables d, m, j, and o are declared. Variables m and j are initialized to 0 and 1, respectively, to represent the first two terms of the Fibonacci series, and o is used to store the next term in the series.

Program Description

The program prints a description message for the user to understand its functionality and explains what the Fibonacci series is.

User Input

The user is prompted to enter a number up to which they want to generate the Fibonacci series. The input is read using scanf("%d", &d);.

Fibonacci Series Calculation

The program starts the Fibonacci series with the first two terms (0 and 1) and calculates the subsequent terms using a while loop:

printf("Fibonacci Series till the entered number %d is: %d, %d, ", d, m, j);: Prints the first two terms.
o = m + j;: Calculates the next term in the series.
while (o <= d): Continuously checks if the next term o is less than or equal to the entered number d.
printf(", %d", o);: Prints the current term o.
m = j;: Updates m to the value of j.
j = o;: Updates j to the value of o.
o = m + j;: Calculates the next term in the series.

Program End

The program ends with printf("\n"); to print a new line and return 0; to indicate successful execution.

Code

                    
/*
 * -----------------------------------------------------------
 * Logic Building with Computer Programming (CSU1128)
 * Instructor: Dr. Pankaj Vaidya | Author: Divya Mohan
 * 
 * This code is a part of the educational initiative by dmj.one
 * with aim of empowering and inspiring learners in the field of
 * Computer Science and Engineering through the respective courses.
 * 
 * (c) 2022, Divya Mohan for dmj.one. All rights reserved.
 * -----------------------------------------------------------
 */

#include <stdio.h>
int main()
{
    int d, m = 0, j = 1, o = 0;
    printf("\n\n Program to print the fibonacci series till an entered number.");
    printf("Fibonacci series is a series where the number at any point is the sum of previous two numbers.");
    printf("Example 9 = 1 2 3 5 8 \n\n");

    printf("Enter a number till which you want to count the number of digits (Example: 2100) - and press enter: ");
    scanf("%d", &d);

    // display the first two terms which is always 0 and 1
    printf("Fibonacci Series till the entered number %d is: %d, %d, ", d, m, j);
    o = m + j;

    while (o <= d)
    {
        printf(", %d", o);
        m = j;
        j = o;
        o = m + j;
    }
    printf("\n");
    return 0;
}

Output

Program to print the fibonacci series till an entered number. Fibonacci series is a series where the number at any point is the sum of previous two numbers. Example 9 = 1 2 3 5 8

Enter a number till which you want to count the number of digits (Example: 2100) - and press enter: 44
Fibonacci Series till the entered number 44 is: 0, 1, , 1, 2, 3, 5, 8, 13, 21, 34