Program to print Reverse Floyd’s triangle

Floyd’s triangle is a triangle with first natural numbers. Task is to print reverse of Floyd’s triangle.
Examples:

Input : 4
Output :
10 9 8 7
6 5 4 
3 2 
1 

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

C++

// CPP program to print reverse of
// floyd's triangle
#include <bits/stdc++.h>
using namespace std;

void printReverseFloyd(int n)
{
    int curr_val = n * (n + 1) / 2;
    for (int i = n; i >= 1; i--) {
        for (int j = i; j >= 1; j--) {
            cout << setprecision(2);
            cout << curr_val-- << "  ";
        }

        cout << endl;
    }
}

// Driver's Code
int main()
{
    int n = 7;
    printReverseFloyd(n);
    return 0;
}

// this article is contributed by manish kumar rai

Java

// Java program to print reverse of
// floyd's triangle
import java.io.*;

class GFG {
    static void printReverseFloyd(int n)
    {
        int curr_val = n * (n + 1) / 2;
        for (int i = n; i >= 1; i--) {
            for (int j = i; j >= 1; j--) {
                System.out.printf("%2d  ", curr_val--);
            }

            System.out.println("");
        }
    }

    // Driver method
    public static void main(String[] args)
    {
        int n = 7;
        printReverseFloyd(n);
    }
}
// this article is contributed by manish kumar rai

Python3

# Python3 program to print reverse of
# floyd's triangle
def printReverseFloyd(n):

    curr_val = int(n*(n + 1)/2)
    for i in range(n + 1, 1, -1):
        for j in range(i, 1, -1):
            print(curr_val, end ="  ")
            curr_val -= 1

        print("")

# Driver code
n = 7
printReverseFloyd(n)

C#

// C# program to print reverse
// of floyd's triangle
using System;
using System.Globalization;

class GFG
{
    static void printReverseFloyd(int n)
    {
        int curr_val = n * (n + 1) / 2;
        for (int i = n; i >= 1; i--)
        {
            for (int j = i; j >= 1; j--)
            {
                Console.Write(curr_val-- + " ");
            }

            Console.WriteLine("");
        }
    }

    // Driver Code
    public static void Main()
    {
        int n = 7;
        printReverseFloyd(n);
    }

}

// This code is contributed by Sam007

PHP

<?php
// PHP program to print reverse
// of floyd's triangle
function printReverseFloyd($n)
{
    $curr_val = $n * ($n + 1) / 2;
    for ($i = $n; $i >= 1; $i--)
    {
        for ( $j = $i; $j >= 1; $j--)
        {
            echo $curr_val-- , " ";
        }

        echo " \n";
    }
}

// Driver Code
$n = 7;
printReverseFloyd($n);

// This code is contributed by ajit
?>

Javascript

<script>

// Javascript program to print reverse of
// floyd's triangle

function printReverseFloyd(n)
    {
        let curr_val = n * (n + 1) / 2;
        for (let i = n; i >= 1; i--) {
            for (let j = i; j >= 1; j--) {
                document.write(curr_val-- + " ");
            }

            document.write("<br/>");
        }
    }


// Driver Code

          let n = 7;
        printReverseFloyd(n);

</script>

Output:

28  27  26  25  24  23  22  
21  20  19  18  17  16  
15  14  13  12  11  
10  9  8  7  
6  5  4  
3  2  
1

Time complexity: O(n²) for given input n

Auxiliary space: O(1)