📜  求第一个以N为中心的八角形数的总和

📅  最后修改于: 2021-05-07 08:54:46             🧑  作者: Mango

给定数字N,任务是找到前N个中心八角形数字的总和。

例子:

方法:

  1. 最初,我们需要创建一个函数,该函数将帮助我们计算第N居中的八边形数。
  2. 现在,运行一个从1到N的循环,以找到i居中的八边形数字。
  3. 将所有以上计算的居中八角形数字相加。
  4. 最后,显示前N个居中的八角形数字的总和。

下面是上述方法的实现:

C++
// C++ program to find the sum of the
// first N centered octagonal number
#include
using namespace std;
 
// Function to find the N-th centered
// octagonal number
int center_Octagonal_num(int n)
{
 
    // Formula to calculate
    // nth centered octagonal
    // number
    return (4 * n * n - 4 * n + 1);
}
 
// Function to find the sum of the first
// N centered octagonal numbers
int sum_center_Octagonal_num(int n)
{
 
    // Variable to store
    // the sum
    int summ = 0;
 
    // Iterating through the range
    // 1 to N
    for(int i = 1; i < n + 1; i++)
    {
       summ += center_Octagonal_num(i);
    }
    return summ;
}
 
// Driver Code
int main()
{
    int n = 5;
 
    cout << (sum_center_Octagonal_num(n));
    return 0;
}
 
// This code is contributed by PratikBasu


Java
// Java program to find the sum of the
// first N centered octagonal number
class GFG {
     
// Function to find N-th centered
// octagonal number
static int center_Octagonal_num(int n)
{
 
    // Formula to calculate
    // nth centered octagonal
    // number
    return (4 * n * n - 4 * n + 1);
}
 
// Function to find the
// sum of the first N
// centered octagonal
// numbers
static int sum_center_Octagonal_num(int n)
{
 
    // Variable to store
    // the sum
    int summ = 0;
 
    // Iterating through the first N
    // numbers
    for(int i = 1; i < n + 1; i++)
    {
       summ += center_Octagonal_num(i);
    }
    return summ;
}
 
// Driver code
public static void main(String[] args)
{
    int n = 5;
 
    System.out.println(sum_center_Octagonal_num(n));
}
}
 
// This code is contributed by Princi Singh


Python3
# Python3 program to find the
# sum of the first N
# Centered Octagonal number
 
# Function to find N-th
# Centered Octagonal
# number
def center_Octagonal_num(n):
 
    # Formula to calculate 
    # nth centered Octagonal
    # number
    return (4 * n * n - 4 * n + 1)
     
   
# Function to find the
# sum of the first N
# Centered Octagonal
# numbers
def sum_center_Octagonal_num(n) :
     
    # Variable to store
    # the sum
    summ = 0
     
    # Iterating through the first N
    # numbers
    for i in range(1, n + 1):
 
        summ += center_Octagonal_num(i)
     
    return summ
   
# Driver code
if __name__ == '__main__' :
           
    n = 5
     
    print(sum_center_Octagonal_num(n))


C#
// C# program to find the sum of the
// first N centered octagonal number
using System;
 
class GFG{
     
// Function to find N-th centered
// octagonal number
static int center_Octagonal_num(int n)
{
 
    // Formula to calculate
    // nth centered octagonal
    // number
    return (4 * n * n - 4 * n + 1);
}
 
// Function to find the sum of
// the first N centered octagonal
// numbers
static int sum_center_Octagonal_num(int n)
{
 
    // Variable to store
    // the sum
    int summ = 0;
 
    // Iterating through the first N
    // numbers
    for(int i = 1; i < n + 1; i++)
    {
       summ += center_Octagonal_num(i);
    }
    return summ;
}
 
// Driver code
public static void Main()
{
    int n = 5;
 
    Console.WriteLine(sum_center_Octagonal_num(n));
}
}
 
// This code is contributed by Akanksha_Rai


Javascript

 
// This code is contributed by divyeshrabadiya07.


输出:
165

时间复杂度: O(N)。