Seminario_TP3_EJ08

a)
(defun SumaDiagMatriz  (l1 &optional (l2 0))
    (if (null l1) 0
        (+ (nth l2 (car l1)) (SumaDiagMatriz (cdr l1) (+ l2 1)))
    )
)

b)
(defun OtraDiagonal (matriz)

    (defun ultimo (lista &optional (salida -1))
        (if (null lista) salida
            (ultimo (cdr lista) (+ salida 1))
        )
    )
    (if (null matriz) nil
        (cons (nth (ultimo matriz) (car matriz)) (OtraDiagonal (cdr matriz)))
    )
)

c)
(defun traspuesta (l)

    (defun cab (l)
        (if (null l) nil
            (cons (caar l) (cab (cdr l)))
        )
    )

    (defun quitacab (l)
        (if (null l) nil
            (append (list (cdar l)) (quitacab (cdr l)))
        )
    )

    (if (null (car l)) nil
        (append (list (cab l))(traspuesta (quitacab l)))
    )
)