给定数字N ,任务是找到前N个中心七边形数字的总和。
The first few Centered heptagonal number are 1, 8, 22, 43, 71, 106, 148, …
例子:
Input: N = 3
Output: 31
Explanation:
1, 8 and 22 are the first three centered heptagonal numbers.
Input: N = 5
Output: 145
方法:
- 最初,我们需要创建一个函数,该函数将帮助我们计算第N个中心的七边形数。
- 现在,运行一个从1到N的循环,以找到第i个居中的七边形数。
- 将所有以上计算的居中七边形数相加。
- 最后,显示前N个居中的七边形数字的总和。
下面是上述方法的实现:
C++
// C++ program to find the sum of the
// first N centered heptagonal numbers
#include
using namespace std;
// Function to find the N-th centered
// heptagonal number
int center_heptagonal_num(int n)
{
// Formula to calculate
// nth centered heptagonal
// number
return (7 * n * n - 7 * n + 2) / 2;
}
// Function to find the sum of the first
// N centered heptagonal numbers
int sum_center_heptagonal_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_heptagonal_num(i);
}
return summ;
}
// Driver Code
int main()
{
int n = 5;
cout << (sum_center_heptagonal_num(n));
return 0;
}
// This code is contributed by PratikBasu
Java
// Java program to find the sum of the
// first N centered heptagonal numbers
class GFG{
// Function to find the N-th centered
// heptagonal number
public static int center_heptagonal_num(int n)
{
// Formula to calculate
// nth centered heptagonal
// number
return (7 * n * n - 7 * n + 2) / 2;
}
// Function to find the sum of the first
// N centered heptagonal numbers
public static int sum_center_heptagonal_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_heptagonal_num(i);
}
return summ;
}
// Driver Code
public static void main(String args[])
{
int n = 5;
System.out.print(sum_center_heptagonal_num(n));
}
}
// This code is contributed by Code_Mech
Python3
# Python3 program to find the sum
# of the first N centered
# heptagonal numbers
# Function to find N-th
# centered heptagonal
# number
def center_heptagonal_num(n):
# Formula to calculate
# nth centered heptagonal
# number
return (7 * n * n - 7 * n + 2) // 2
# Function to find the
# sum of the first N
# centered heptagonal
# numbers
def sum_center_heptagonal_num(n) :
# Variable to store
# the sum
summ = 0
# Iterate through the range
# 1 to N
for i in range(1, n + 1):
summ += center_heptagonal_num(i)
return summ
# Driver code
if __name__ == '__main__' :
n = 5
print(sum_center_heptagonal_num(n))
C#
// C# program to find the sum of the
// first N centered heptagonal numbers
using System;
class GFG{
// Function to find the N-th centered
// heptagonal number
public static int center_heptagonal_num(int n)
{
// Formula to calculate
// nth centered heptagonal
// number
return (7 * n * n - 7 * n + 2) / 2;
}
// Function to find the sum of the first
// N centered heptagonal numbers
public static int sum_center_heptagonal_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_heptagonal_num(i);
}
return summ;
}
// Driver Code
public static void Main()
{
int n = 5;
Console.Write(sum_center_heptagonal_num(n));
}
}
// This code is contributed by Akanksha_Rai
Javascript
// This code is contributed by divyeshrabadiya07.
输出:
145
时间复杂度: O(N)。