给定数字n,任务是找到第n个二十进制正弦数(Isdn)。
多边形有很多多边形,取决于它们的角数系列。在数学中,有许多个gonal数,而二十进制正角数是其中之一,并且这些数具有22面的多边形(icosidigon)。二十进制数属于图形数类。它们具有一个共同的点点,而其他点图案则按第n个嵌套二十进制图案排列。
例子 :
Input : 2
Output :22
Input :6
Output :306
第n个余弦正弦数的公式:
C++
// C++ program to find nth Icosidigonal
// number
#include
using namespace std;
// Function to calculate Icosidigonal number
int icosidigonal_num(long int n)
{
// Formula for finding
// nth Icosidigonal number
return (20 * n * n - 18 * n) / 2;
}
// Driver function
int main()
{
long int n = 4;
cout << n << "th Icosidigonal number :" << icosidigonal_num(n);
cout << endl;
n = 8;
cout << n << "th Icosidigonal number:" << icosidigonal_num(n);
return 0;
}
Java
// Java program to find nth
// Icosidigonal number
import java.io.*;
class GFG
{
// Function to calculate
// Icosidigonal number
static int icosidigonal_num(int n)
{
// Formula for finding
// nth Icosidigonal number
return (20 * n * n - 18 * n) / 2;
}
// Driver Code
public static void main (String[] args)
{
int n = 4;
System.out.print (n + "th Icosidigonal number :");
System.out.println (icosidigonal_num(n));
n = 8;
System.out.print (n + "th Icosidigonal number :");
System.out.println (icosidigonal_num(n));
}
}
// This code is contributed by ajit
Python 3
# python 3 program to find
# nth Icosidigonal number
# Function to calculate
# Icosidigonal number
def icosidigonal_num(n) :
# Formula for finding
# nth Icosidigonal number
return (20 * n * n -
18 * n) // 2
# Driver Code
if __name__ == '__main__' :
n = 4
print(n,"th Icosidigonal " +
"number : ",
icosidigonal_num(n))
n = 8
print(n,"th Icosidigonal " +
"number : ",
icosidigonal_num(n))
# This code is contributed m_kit
C#
// C# program to find nth
// Icosidigonal number
using System;
class GFG
{
// Function to calculate
// Icosidigonal number
static int icosidigonal_num(int n)
{
// Formula for finding
// nth Icosidigonal number
return (20 * n * n -
18 * n) / 2;
}
// Driver Code
static public void Main ()
{
int n = 4;
Console.Write(n + "th Icosidigonal " +
"number :");
Console.WriteLine(icosidigonal_num(n));
n = 8;
Console.Write (n + "th Icosidigonal "+
"number :");
Console.WriteLine(icosidigonal_num(n));
}
}
// This code is contributed by ajit
PHP
Javascript
输出 :
4th Icosidigonal number :124
8th Icosidigonal number:568
参考:https://en.wikipedia.org/wiki/Polygonal_number