def reverser(streng):
    reversertStreng = ""
    for i in range(len(streng)-1, -1, -1):
        reversertStreng += streng[i]
    return reversertStreng


def testReverser():
    assert reverser("hei") == "ieh"
    assert reverser("Agnes i senga") == "agnes i sengA"
    assert reverser("") == ""
    print("Sukess?\n G? til neste niv?!")


testReverser()


def erPanagram(setning):
    for bokstav in "aqwertyuiop?asdfghjkl??zxcvbnm":
        if bokstav not in setning:
            return False
    return True


def testPangram():
    assert erPanagram(
        "Jeg begynte ? fort?re en sandwich mens jeg kj?rte taxi p? vei til quiz")
    assert erPanagram(
        "Jeg begynte ? fort?re en sandwich mens jeg kj?rte taxi p? vei til middag") == False
    print("Sukess?\n G? til neste niv?!")


testPangram()


def erParNaboTall(x, y):
    return abs(x-y) == 1


def testParNaboTall():
    assert erParNaboTall(1, 2)
    assert not erParNaboTall(1, 3)
    assert erParNaboTall(2, 1)
    assert not erParNaboTall(0, 0)
    assert not erParNaboTall(9, 11)
    print("Sukess?\n G? til neste niv?!")


testParNaboTall()


def antallNabotallIListe(liste):
    antall = 0
    for i in range(0, len(liste)-1, 2):
        if i == len(liste)-1:
            return antall
        if erParNaboTall(liste[i], liste[i+1]):
            antall += 1
    return antall


def testAntallNabotallIListe():
    assert antallNabotallIListe([1, 2, 3, 1, 2, 9]) == 1
    assert antallNabotallIListe([1, 2, 3, 4, 2, 9, 6]) == 2
    assert antallNabotallIListe([1, 2, 3, 4, 10, 9, 6]) == 3
    assert antallNabotallIListe([1]) == 0
    print("Sukess?\n G? til neste niv?!")


testAntallNabotallIListe()


def tallTilBokstaver(tall):
    tallMapping = {
        "-": "minus",
        "0": "null",
        "1": "en",
        "2": "to",
        "3": "tre",
        "4": "fire",
        "5": "fem",
        "6": "seks",
        "7": "syv",
        "8": "?tte",
        "9": "ni"
    }
    strengTall = str(tall)
    tallIOrd = []
    for t in strengTall:
        tallIOrd.append(tallMapping[t])
    return " ".join(tallIOrd)


def testTallTilBokstaver():
    assert tallTilBokstaver(1) == "en"
    assert tallTilBokstaver(19) == "en ni"
    assert tallTilBokstaver(0) == "null"
    assert tallTilBokstaver(-1) == "minus en"
    print("Sukess?\n G? til neste niv?!")


testTallTilBokstaver()