Pyramid pattern algorithm developing

Question

I was doing some hackerrank practice and I couldnt solve it. I am newbie any ideas to solve this problem?

Please write a software program that prints the following pyramid pattern to the screen. Your program should get a number “n” as an input and should print n lines of the pyramid. (For example if your input is 4, then the following output is expected.)

(You can choose any programming language that you want.)

      1
    2 3 2
  3 4 5 4 3
4 5 6 7 6 5 4


#include<stdio.h>

int main()
{
    int i,j,k,l=1;
    for(i=1; i<=5; i++)
    {
        for(j=4; j>=i; j--)
        {
            printf(" ");
        }
        
        for(k=1; k<=l; k++)
        { 
            printf("%d",k);
        }            
            l = l+2;    
        printf("\n");
    }
    return 0;
}

Answer 1

These types of problems can be solved by simple mathematics.

I would advice you to solve this by problem by breaking it into simpler and smaller use cases as follows:

1. Number of blank spaces on each line.

2. Number of Elements (on each line) until the centre of pyramid.

3. Number of Elements (on each line) after the centre of pyramid.

    #include<stdio.h>
   
    int main()
    {
        int N;
        scanf("%d", &N);
   
        int numberOfBlankSpaces = N + 2;
   
        for(int i=1; i<=N ;i++){    
   
            for(int j=0;j<numberOfBlankSpaces;j++){
                printf(" ");
            }
   
            numberOfBlankSpaces -= 2;
   
            int number_of_elements_until_centre_on_each_line = i;
            int startingElement = i;
   
            //Print increasing order until center
            while(number_of_elements_until_centre_on_each_line--){
                printf("%d ", startingElement);
                startingElement++;
            }
   
            // Starting element = Element at center - 1 
            startingElement-=2;
   
            //Print decresing order
            while(startingElement >= i){
                printf("%d ", startingElement);
                startingElement--;
            }
   
            printf("\n");
        }
   
        return 0;
    }
   

Input: 4

Output:

      1 
    2 3 2 
  3 4 5 4 3 
4 5 6 7 6 5 4