module linear
    implicit none

    contains

    subroutine jacobi(A,x,b,n,k)
        implicit none
        integer, intent(in) ::n,k
        real, intent(in)  ::A(n,n),b(n)
        real, intent(out) ::x(n)

        integer :: iter ,i,j
        real :: s

        x=0.
        do iter=1,k

            do i=1,n
                s=0.
                do j=1,n

                    if (j.ne.i) then
                        s=s+A(i,i)**(-1)*A(i,j)*x(j)
                    end if 

                end do
            
                x(i)=-s+A(i,i)**(-1)*b(i)

            end do 
        
        end do

    end subroutine jacobi

end module linear