Question

What I want to do is to find every permutation of a 1-d array with repetitions of its contents.

e.g.

int array[]={1,2,3};
for(i=0;i<3;i++){
    next_permutation(array,array+3)
    for(int j=0;j<=3;j++){
        printf("%d ",array[j]);
    }
printf("\n");
}

will return:

1 2 3
1 3 2
2 1 3
etc...

what I want the function to return:

1 1 1
1 1 2
1 2 1
2 1 1
1 2 2
2 2 1
2 1 2
1 1 3
1 3 1
3 1 1
etc...

Is there a function that can do that?

Thanks in advance,
Erik

Answer 1

You are not doing permutation but just counting.

Ex. if your enumerating set {0, 1} over 3 digits, you’ll get:

000
001
010
011
100
101
110
111

See, that’s just binary counting.

So map your element set into n-digits, then do n-based count will give you the right awnser