Floyd's Triangle in C

This C program will ask the user to enter the number of rows and will return a floyd's triangle for the same height.

Floyd's Triangle #

A Floyd's triangle is a triangle in which each number is the sum of the two numbers above it. For example, the first row of the Floyd's triangle is 1, the second row is 2 + 1 = 3, the third row is 4 + 5 = 9, and so on. The following is a diagram of the Floyd's triangle:

1

2 3 4 5 6 7 8 9 10

Algorithm #

1. Take the number of rows as input.
2. Store the number of rows in a variable.
3. Create a for loop to loop through the number of rows.
4. Print the elements for every row.

Problem description #

Given the number of rows, this program will return a floyd's triangle for the same height.

Examples #

Input : 3 Output : 1 2 3 4 5 6

Input : 5 Output : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Problem Solution #

To approach this problem, we'll use a for loop to loop through the number of rows and print the elements for every row by incrementing the number of rows by 1.

Methods used #

Approach #

1. Take the number of rows as input.
2. Store the number of rows in a variable.
3. Create a for loop to loop through the number of rows.
4. Print the elements for every row.

Program/Source code #

/* Program to print the floyd's triangle */

#include <stdio.h>

void floyds_triangle(int rows)
{
	int i, j, k = 1;

	for (i = 1; i <= rows; i++) {
		for (j = 1; j <= i; j++) {
			printf("%4.d ", k ++);
		}
		printf("\n");
	}
}

int main(void)
{
	int rows;

	printf("Enter the number of rows: ");
	scanf("%d", &rows);

	floyds_triangle(rows);

	return 0;
}

Explanation #

The program will ask the user to enter the number of rows and will return a floyd's triangle for the same height. The program will print the elements for every row by incrementing the number of rows by 1.

Time complexity #

The time complexity of this program is O(n).

Space Complexity #

The space complexity of this program is O(1).

Output #

> ./floyds_triangle      
Enter the number of rows: 5
   1 
   2    3 
   4    5    6 
   7    8    9   10 
  11   12   13   14   15 

  > ./floyds_triangle
Enter the number of rows: 12
   1 
   2    3 
   4    5    6 
   7    8    9   10 
  11   12   13   14   15 
  16   17   18   19   20   21 
  22   23   24   25   26   27   28 
  29   30   31   32   33   34   35   36 
  37   38   39   40   41   42   43   44   45 
  46   47   48   49   50   51   52   53   54   55 
  56   57   58   59   60   61   62   63   64   65   66 
  67   68   69   70   71   72   73   74   75   76   77   78