perestanovka_leksikografich

def NextPermutationAlgorithm(w):
    l = len(w)
    b = w
    r = None

    i=l-1

    while (i>0):
        if (b[i-1] > b[i]):
            pv = i

            j = pv
            while (j < l):
                if (b[j] <= b[pv] & b[i-1] < b[j]):
                    pv = j
                j+=1
            b[i-1], b[pv] = b[pv], b[i-1]

            j= l-1
            while (i < j):
                b[i], b[j] = b[j], b[i]
                i, j = i+1, j-1
            r = str(b)
            break
        i -= 1
    return r

d = [4,3,2,1]


print(d)
while (1):
    q = NextPermutationAlgorithm(d)
    if q is None:
        break
    else:
        print(q)