C Exercises: Display the first 10 lucus numbers

C Numbers: Exercise-11 with Solution

Write a program in C to display the first 10 lucus numbers.

Sample Solution:

C Code:

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

int main() 
{
    printf("\n\n Find the first 10 Lucas numbers: \n"); // Print message to find Lucas numbers
    printf(" -------------------------------------\n"); // Print separator
    printf(" The first 10 Lucas numbers are: \n"); // Print message

    int n = 10; // Number of Lucas numbers to generate
    int n1 = 2, n2 = 1, n3; // Initialize the first two Lucas numbers

    if (n > 1) // Check if the number of Lucas numbers is greater than 1
    {
        printf("%d %d ", n1, n2); // Print the first two Lucas numbers

        for (int i = 2; i < n; ++i) // Loop to generate remaining Lucas numbers
        {
            n3 = n2; // Store the value of n2 in n3
            n2 += n1; // Calculate the next Lucas number by adding the previous two
            n1 = n3; // Update n1 to the previous n2
            printf("%d ", n2); // Print the current Lucas number
        } 
        printf("\n"); // Print newline after printing all Lucas numbers
    }
    else if (n == 1) // Check if only one Lucas number is to be generated
    {
        printf("%d ", n2); // Print the first Lucas number
        printf("\n"); // Print newline after printing the Lucas number
    }
    else // If input is less than 1
    { 
        printf("Input a positive number.\n"); // Print message to input a positive number
    }

    return 0; // Return 0 to indicate successful execution
}

Sample Output:

 The first 10 Lucus numbers are:                                                                              
2 1 3 4 7 11 18 29 47 76

Flowchart:

C Programming Code Editor:

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