Floyd’s triangle in C

Floyd’s triangle in C

Floyd’s triangle is named after a person Robert Floyd. It is a right-angled triangle that is of natural numbers starting from 1 and consecutively selects the upcoming more significant number in the sequence. It can also be defined as filling the rows of a triangle with consecutive numbers, starting with the number 1 on the top left corner.

E.g.:

            1
            2  3
            4  5  6
            7  8  9  10 

Algorithm:

Step 1: input the number of rows to be printed. Let us consider the variable ‘n’ for it.

Step 2: initialize another variable ‘i’ and iterate it for ‘n’ times. This will later print the rows.

Step 3: initialize another variable ‘j’ and iterate it for inner iterations.

Step 4: initialize and print a variable named ‘k’.

Step 5: increment the initialized variable ‘k’.

Step 6: include a newline character (escape sequence) after each iteration.

Step 7: return.

Pseudocode:

A pseudocode is a notation resembling a simplified programming language that is used in program design. Pseudocode for Floyd’s triangle is:

 start
 for i = 1 to n do
             for j = 1 to i do
 print k
 increment k
             end for
             print newline
             end for
             end 

Program code to get floyd’s triangle:

 #include <stdio.h>
 #include <conio.h>
 #include <math.h>
 int main()
 {
 int n, i, j;
 int n = 5;
 int k = 1;
 for (1 = 1; i <= n; i++)
 {
 for (j = 1; j <= i; j++)
 {
 printf (“ %3d”, k++);
 }
 printf (“\n”);
 }
 return 0;
 } 

Output:

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

 #include <stdio.h>
 #include <conio.h>
 #include <math.h>
 int main()
 {
 int n, i, j;
 int k = 1;
 printf (“Enter the number of rows of the Floyd’s triangle to be printed \n”);
 for (1 = 1; i <= n; i++)
 {
 for (j = 1; j <= i; j++)
 {
 printf (“ %3d”, k);
 k++;
 }
 printf (“\n”);
 }
 return 0;
 } 

Output:

 Enter the number of rows of the Floyd’s triangle to be printed:
 7
 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 

• The above program codes print right angled Floyd’s triangle.
• The only loop used to execute and try this is for loop.
• The header files used are stdio.h and conio.h using the “inlcude” preceding with # which infer that the header files need to be accessed before the compilation. There are called the preprocessor directives. Stdio header is used for standard input output. This is used for getting the input from the user (keyboard) and output the result to the monitor (screen). Conio header file is used in old MS_DOS compilers to create a text user interface. It will not be a part of the C programming language.
• The main() function is declared with the return type as an integer. Declare four variables ‘n’, ‘i’, ‘j’, ‘k’ and assign the value of ‘k’ to 1.
• The printf() function is used for displaying the message “Enter the number of rows for required structure of floyd’s triangle”. Read the same using scanf() function which fetches the value from the user and stores it in variable ‘n’.
• Include two loops in the form of nested for. First for loop will count using the variable ‘i’ as 1 and check the condition i <= n. Again, the second nested for loop going from k = 1 till k <= i.
• Then output the function which is used within nested for to print all the numbers and increment the value of ‘k’ by 1.
• Once the inner loop is executed, printf() will take over the printing cursor to the next line using the escape sequence or newline character ‘\n’.

Reverse of Floyd’s triangle:

 #include <stdio.h>
 #include <conio.h>
 int main()
 {
 int i, j, n;
 printf (“Enter the number of rows to be printed in the Floyd’s triangle: \n”);
 scanf (“%d”, &n);
 printf (“Reverse of Floyd’s triangle is: \n”);
 int k = (n * (n + 1)) /2;
 for (i = n; i >= 1; i--)
 {
 for (j = i; j >= 1; j--)
 {
 printf (“ %4d”, k);
 K--;
 }
 printf (“\n”);
 }
 return 0;
 } 

Output:

 Enter the number of rows to be printed in the Flyod’s triangle:
 5
 Reverse of Floyd’s triangle is:
 10    9   8   7
 6     5   4 
 3     2  
 1