Tag: stars

C Program To Draw Pyramid of Stars, using For Loop

Lets write a C program to draw / print / display a pyramid / triangle formed from stars, using nested for loop.

Related Read:
Nested For Loop In C Programming Language
C Program To Draw Pyramid of Stars, using While Loop

Expected Output for the Input

User Input:
Enter no of rows of Pyramid
5

Output:

    
     *
    ***
   *****
  *******
 *********

Pyramid With 20 Rows
pyramid of stars

Video Tutorial: C Program To Draw Pyramid of Stars, using For Loop


[youtube https://www.youtube.com/watch?v=omDJLEDBZNw]

YouTube Link: https://www.youtube.com/watch?v=omDJLEDBZNw [Watch the Video In Full Screen.]

Logic To Draw Pyramid of Stars, using For Loop

If num = 5;

First Iteration of outer for loop
row = 1;

1st inner for loop
condition:
num – row;
= 5 – 1
= 4
Four spaces gets printed.

2st inner for loop
condition:
2 * row – 1;
= 2 * 1 – 1;
= 2 – 1
= 1
One star gets printed.

Second Iteration of outer for loop
row = 2;

1st inner for loop
condition:
num – row;
= 5 – 2
= 3
Three spaces gets printed.

2st inner for loop
condition:
2 * row – 1;
= 2 * 2 – 1;
= 4 – 1
= 3
Three stars gets printed.

Third Iteration of outer for loop
row = 3;

1st inner for loop
condition:
num – row;
= 5 – 3
= 2
Two spaces gets printed.

2st inner for loop
condition:
2 * row – 1;
= 2 * 3 – 1;
= 6 – 1
= 5
Five stars gets printed.

Forth Iteration of outer for loop
row = 4;

1st inner for loop
condition:
num – row;
= 5 – 4
= 1
One space gets printed.

2st inner for loop
condition:
2 * row – 1;
= 2 * 4 – 1;
= 8 – 1
= 7
Seven stars gets printed.

Fifth Iteration of outer for loop
row = 5;

1st inner for loop
condition:
num – row;
= 5 – 5
= 0
Zero space gets printed.

2st inner for loop
condition:
2 * row – 1;
= 2 * 5 – 1;
= 10 – 1
= 9
Nine stars gets printed.

Source Code: C Program To Draw Pyramid of Stars, using For Loop

#include<stdio.h>

int main()
{
    int num, row, col, space;

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

    for(row = 1; row <= num; row++)
    {
        for(space = 1; space <= (num-row); space++)
        {
            printf(" ");
        }
        for(col = 1; col <= (2*row-1); col++)
        {
            printf("*");
        }
        printf("\n");
    }

    return 0;
}

Output 1:
Enter no of rows of Pyramid
5

     *
    ***
   *****
  *******
 *********

For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert

C Program To Draw Pyramid of Stars, using While Loop

Lets write a C program to draw / print / display a pyramid / triangle formed from stars, using while loop.

Related Read:
while loop in C programming
Nested While Loop: C Program

Expected Output for the Input

User Input:
Enter no of rows of Pyramid
5

Output:

    
     *
    ***
   *****
  *******
 *********

Pyramid With 20 Rows
pyramid of stars

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


[youtube https://www.youtube.com/watch?v=pwLx0cELxY4]

YouTube Link: https://www.youtube.com/watch?v=pwLx0cELxY4 [Watch the Video In Full Screen.]

Logic To Draw Pyramid of Stars, 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 count to 1(indicating first row of the pyramid).

In the outer while loop we check if count is less than or equal to num. For each iteration of the while loop we increment the value of count by 1. So the count 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 stars).

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 stars needed for each row.

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

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

#include<stdio.h>

int main()
{
    int num, count = 1, i;

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

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

        i = 0;
        while(i < (2*count-1))
        {
            printf("*");
            i++;
        }

        printf("\n");
        count++;
    }

    return 0;
}

Output 1:
Enter no of rows of Pyramid
5

     *
    ***
   *****
  *******
 *********

For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert