给定数字N。任务是找到直到N个项的以下系列的和:
1 + 22 + 333 + 4444 + …up to n terms
例子:
Input: N = 3
Output: 356
Input: N = 10
Output: 12208504795
方法:
下面是上述方法的实现:
C++
// CPP program to find the sum
// of given series
#include
#include
using namespace std;
// Function to calculate sum
int findSum(int n)
{
// Return sum
return (pow(10, n + 1) * (9 * n - 1) + 10) /
pow(9, 3) - n * (n + 1) / 18;
}
// Driver code
int main()
{
int n = 3;
cout << findSum(n);
return 0;
}
Java
// Java Program to find
// Sum of first n terms
import java.util.*;
class solution
{
static int calculateSum(int n)
{
// Returning the final sum
return ((int)Math.pow(10, n + 1) * (9 * n - 1) + 10) /
(int)Math.pow(9, 3) - n * (n + 1) / 18;
}
// Driver code
public static void main(String ar[])
{
// no. of terms to find the sum
int n=3;
System.out.println("Sum= "+ calculateSum(n));
}
}
//This code is contributed by Surendra_Gangwar
Python 3
# Python program to find the sum of given series.
# Function to calculate sum
def solve_sum(n):
# Return sum
return (pow(10, n + 1)*(9 * n - 1)+10)/pow(9, 3)-n*(n + 1)/18
# driver code
n = 3
print(int(solve_sum(n)))
C#
// C# Program to find
// Sum of first n terms
using System;
class solution
{
static int calculateSum(int n)
{
// Returning the final sum
return ((int)Math.Pow(10, n + 1) * (9 * n - 1) + 10) /
(int)Math.Pow(9, 3) - n * (n + 1) / 18;
}
// Driver code
public static void Main()
{
// no. of terms to find the sum
int n=3;
Console.WriteLine("Sum= "+ calculateSum(n));
}
}
//This code is contributed by inder_verma.
PHP
Javascript
输出:
356