Even number pattern 2 in C

Categories C programming 2 mins read

Write a C program to print the given even number pattern using loop. How to print the given even number pattern using for loop in C programming. Logic to print the given number pattern in C program.

Example

Input

Input N: 5

Output

2
242
24642
2468642
2468108642


    2
   242
  24642
 2468642
2468108642

Required knowledge

Basic C programming , Loop

Logic to print the given even number pattern

2
242
24642
2468642
2468108642

To get the logic of the pattern have a close look on to the pattern. You can observe following things about the pattern.

  1. The pattern consists of total N rows (where N is the total number of rows to be printed).
  2. To make things little easier let’s divide the pattern in two internal parts.

    2
24 
246  
2468   
246810


     
  2
   42
    642
     8642

  3. Loop formation to print the first part of the pattern will be for(j=2; j<=i*2; i+=2).
  4. Loop formation to print the second part of the pattern will be for(j=(i-1)*2; j>=2; j-=2).

Let’s combine the logic of both parts in single program.

Program to print the given even number pattern

/**
 * C program to print the given number pattern
 */

#include <stdio.h>

int main()
{
    int i, j, N;

    printf("Enter rows: ");
    scanf("%d", &N);

    for(i=1; i<=N; i++)
    {
        // Prints first part of the pattern
        for(j=2; j<=i*2; j+=2)
        {
            printf("%d", j);
        }

        // Prints second part of the pattern
        for(j=(i-1)*2; j>=2; j-=2)
        {
            printf("%d", j);
        }

        printf("\n");
    }

    return 0;
}

Output

Enter rows: 5
2
242
24642
2468642
2468108642

Once you get the logic of above pattern you can easily print the second pattern. You just need to add extra space before printing the numbers.

    2
   242
  24642
 2468642
2468108642

Program to print the above pattern

/**
 * C program to print the given number pattern
 */

#include <stdio.h>

int main()
{
    int i, j, N;

    printf("Enter rows: ");
    scanf("%d", &N);

    for(i=1; i<=N; i++)
    {
        // Prints space
        for(j=i; j<N; j++)
        {
            printf(" ");
        }

        // Prints first part of the pattern
        for(j=2; j<=i*2; j+=2)
        {
            printf("%d", j);
        }

        // Prints second part of the pattern
        for(j=(i-1)*2; j>=2; j-=2)
        {
            printf("%d", j);
        }

        printf("\n");
    }

    return 0;
}

Happy coding 😉