pc-ip-03.c

Problem Statement

pc-ip-03.c

Question 3: Write a program to compute the sum of the first n terms of the series using a function: S=1-2+3-4+5-6+...

Source Code

#include <stdio.h>

int series(int);

int main()
{
    int n;
    printf("Enter the n: ");
    scanf("%d", &n);
    printf("\nSum of the series: %d", series(n));
    return 0;
}

int series(int n)
{
    int i, result = 0;
    for (i = 1; i <= n; i++)
    {
        if (i % 2 == 0)
        {
            result -= i;
        }
        else
        {
            result += i;
        }
    }
    return result;
}

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● Author - Amit Dutta · Updated - 05 Jan 2026