include xpllib; \for Print and StrLen

define Maxx = 12;
char Super;
int  Pos, Cnt(Maxx);

func FactSum(N);        \1! + 2! + ... + n!
int  N, S, X, F;
[S:= 0;  X:= 0;  F:= 1;
while X < N do
    [X:= X+1;
    F:= F*X;
    S:= S+F;
    ];
return S;
];

func R(N);
int  N, C;
[if N = 0 then return false;
C:= Super(Pos - N);
Cnt(N):= Cnt(N)-1;
if Cnt(N) = 0 then
    [Cnt(N):= N;
    if R(N-1) = 0 then return false;
    ];
Super(Pos):= C;  Pos:= Pos+1;
return true;
];

proc Superperm(N);
int  N, I, Len;
[Pos:= N;
Len:= FactSum(N);
Super:= ReallocMem(Super, Len+1);
Super(Len):= 0;
for I:= 0 to N do Cnt(I):= I;
for I:= 1 to N do Super(I-1):= I+^0;
while R(N) do [];
];

int N;
[Super:= 0;
for N:= 0 to Maxx-1 do
    [Print("Superperm(%d) ", N);
    Superperm(N);
    Print("len = %d", StrLen(Super));
    \Uncomment next line to see the string itself
    \Print(": %s", Super);
    CrLf(0);
    ];
]