CGPA counter in C

#include<stdio.h>

int main()

{

    int n,i;

    double sub_grd[100],credit[100];

    double grd=0,total_Credit=0;

    printf("Please Enter Your Total Sub Number: ");

    scanf("%d",&n);

    for(i=1; i<=n; i++)

    {

        printf("Please Enter Your No- %d Sub GPA: ",i);

        scanf("%lf",&sub_grd[i]);

        printf("Please Enter The  No- %d sub Credit: ",i);

        scanf("%lf",&credit[i]);

    }

    /// counting total Credit and  Total Grade

    for(i=1; i<=n; i++)

    {

        grd=grd+(sub_grd[i]*credit[i]);

        total_Credit=total_Credit+credit[i];

    }

    ///Counting the Grade

    grd=grd/total_Credit;

    printf("
Your GPA: %.2lf
",grd);

    return 0;

}