Given maximum of 100 digit numbers as input, find difference between sum of odd and even position

// Find the Nth term in the series

#include <stdio.h>

#include <string.h>

#include <stdlib.h>



int main()

{

    int a = 0,b = 0,i = 0, n;

    char num[100];

   

    printf("Enter the number:");

    scanf("%s",num);    //get the input up to 100 digit

    n = strlen(num);

    while(n>0)

    {

        if(i==0)         //add even digits when no of digit is even and vise versa

        {

            a+=num[n-1]-48;

            n--;

            i=1;

        }

        else            //add odd digits when no of digit is even and vice versa

        {

            b+=num[n-1]-48;

            n--;

            i=0;

        }

    }

    printf("Difference between the sum of odd and even position digits is %d",abs(a-b)); //print the difference of odd and even



    return 0;

}