C Program To Draw Pyramid of Numbers, using While Loop

Lets write a C program to draw / print / display a pyramid / triangle formed from Decimal numbers(0, 1, 2, 3, 4, 5, 6, 7, 8, 9), using while loop.

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Expected Output for the Input

User Input:
Enter the maximum no of rows for Pyramid
5

Output:

    
     0
    123
   45678
  9012345
 678901234

Pyramid With 20 Rows

Video Tutorial: C Program To Draw Pyramid of Numbers, using While Loop

Logic To Draw Pyramid of Numbers, using While Loop

We ask the user to enter the maximum number of rows for the pyramid and store it inside the address of variable num. We declare and initialize a variable row to 1(indicating first row of the pyramid).

In the outer while loop we check if row is less than or equal to num. For each iteration of the while loop we increment the value of row by 1. So the row value will have the row number i.e., for each iteration of the outer while loop we select row one by one (to print the numbers in that selected row).

Inside first inner while loop we print the adequate number of space for each row. Inside the second inner while loop we actually print the numbers needed for each row.

At the end, result will be a pyramid with the number of rows as input by the user.

Source Code: C Program To Draw Pyramid of Numbers, using While Loop

#include < stdio.h >

int main()
{
    int num, i, row = 1, number = 0;

    printf("Enter the maximum no of rows for Pyramid\n");
    scanf("%d", &num);

    while(row <= num)
    {
        i = 0;
        while(i <= (num-row))
        {
            printf(" ");
            i++;
        }

        i = 0;
        while(i < (2*row-1))
        {
            printf("%d", number);

            if(number == 9)
                number = 0;
            else
                number++;

            i++;
        }
        printf("\n");
        row++;
    }
    return 0;
}

Output
Enter the maximum no of rows for Pyramid
14

              0
             123
            45678
           9012345
          678901234
         56789012345
        6789012345678
       901234567890123
      45678901234567890
     1234567890123456789
    012345678901234567890
   12345678901234567890123
  4567890123456789012345678
 901234567890123456789012345

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