# Program to Find sum of series 1-2+3-4+5...+N

Problem statement:- Program to Find the sum of series 1-2+3-4+5-6...+N.

Data requirement:-

Input Data:- n

Output Data:-Sum

Program in C

Here is the source code of the C Program to Find the sum of series 1-2+3-4+5-6...+N.

Code:

#include<stdio.h>
int main()
{
int n;
int sum=0,i;
printf("Enter the range of number:");
scanf("%d",&n);

for(i=1;i<=n;i++)
{
if(i%2==0)
sum-=i;
else
sum+=i;
}

printf("The sum of the series = %d",sum);
}

Input/Output:
Enter the range of number:6
The sum of the series = -3

Program in C++

Here is the source code of the C++ Program to Find the sum of series 1-2+3-4+5-6...+N.

Code:

#include<iostream>
using namespace std;
int main()
{
int n;
int sum=0,i;
cout<<"Enter the range of number:";
cin>>n;

for(i=1;i<=n;i++)
{
if(i%2==0)
sum-=i;
else
sum+=i;
}
cout<<"The sum of the series = "<<sum;
}

Input/Output:
Enter the range of number:4
The sum of the series = -2

Program in Java

Here is the source code of the Java Program to Find the sum of series 1-2+3-4+5-6...+N.

Code:

import java.util.Scanner;
public class Sum_Of_Series2 {

public static void main(String[] args) {
Scanner cs=new Scanner(System.in);
int n;
int sum=0,i;
System.out.println("Enter the range of number:");
n=cs.nextInt();
for(i=1;i<=n;i++)
{
if(i%2==0)
sum-=i;
else
sum+=i;
}
System.out.println("The sum of the series = "+sum);
cs.close();
}
}

Input/Output:
Enter the range of number:
8
The sum of the series = -4

Program in Python

Here is the source code of the Python Program to Find the sum of series 1-2+3-4+5-6...+N.

Code:

n=int(input("Enter the range of number:"))
sum=0
for i in range(1,n+1):
if i % 2 == 0:
sum -= i
else:
sum += i
print("The sum of the series = ",sum)

Input/Output:
Enter the range of number:12
The sum of the series =  -6