The Floyd’s Triangle is a right angled triangle with an array of natural numbers. This article shows how to write a C Program to Print Floyd’s Triangle with an example.
C Program to Print Floyd’s Triangle
This program allows the user to enter the maximum number of rows he/she wants to print as Floyd’s triangle. We are going to print Floyd’s triangle of integers until it reaches the user specified rows.
#include <stdio.h> int main() { int Rows, i, j, Number = 1; printf(" Please Enter the Number of Rows: "); scanf("%d", &Rows); printf(" \n Printing FLOYD'S Triangle \n \n"); for ( i = 1 ; i <= Rows; i++ ) { for ( j = 1 ; j <= i; j++ ) { printf("%d ", Number); Number++; } printf("\n"); } return 0; }

The first two statements allow the user to enter the range or maximum Number of rows he/she want to print.
Now let us see the Nested for loop logic in detail.
Let us see the execution process of C Program to Print Floyd’s Triangle in an iteration wise
Outer Loop – First Iteration
From the above C programming screenshot, you can observe that the value of i is 1 and Rows is 5, and the condition (i <= 5) is True. So, it will enter into the second for loop
Inner Loop – First Iteration
The j value is 1 and the condition (j <= 1) is True. So, it will start executing the statements inside the loop. The following statement will print Number as Output, and we all know that Number = 1 so 1 is printed.
printf("%d ", Number);
The following statement Number++ will increment the Value of Number by 1 using the Increment Operator.
Inner Loop – Second Iteration
The j value will be 2, and the condition (2 <= 1) is False so that it will exit from the second loop. The following announcement is to terminate the current line.
printf("\n");
Outer Loop – Second Iteration
The value of i will be 2, and the condition (2 <=5) is True. So, it will enter into the second for loop
Inner Loop – First Iteration
The value of j is 1, and the condition (1 <= 2) is True. So, it will start executing the statements inside the loop. The following statement will print Number as Output, and we all know that Number = 2, so 2 is printed.
printf("%d ", Number);
The following statement, Number++, will increment the Value of the Number by 1.
Next, the j value will also be incremented by 1.
Inner Loop – Second Iteration
The value of j is 2, and the condition (2 <= 2) is True. So, it will start executing the statements inside the loop. It means 3 will print.
Inner Loop – Third Iteration
The j value will be 3, and the condition (3 <= 2) is False, so it will exit from the second loop.
It happens until it reaches 5, and after that, both the Inner Loop and Outer loop will terminate.
C Program to Display Floyd’s Triangle without Natural numbers
This program allows the user to enter the number of rows he/she want to print as Floyd’s triangle. In this example, we are going to print Floyd’s triangle using the * symbol. This program can also be said to print the Right angled triangles with * symbols.
#include <stdio.h> int main() { int Rows, i, j; printf(" Please Enter the Number of Rows: "); scanf("%d", &Rows); printf(" \n Printing FLOYD'S Triangle \n \n"); for ( i = 1 ; i <= Rows; i++ ) { for ( j = 1 ; j <= i; j++ ) { printf("* "); } printf("\n"); } return 0; }
Please Enter the Number of Rows: 10
Printing FLOYD'S Triangle
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * * * *