Permutation of n-size array with possible repeated elements. E.g [1, 2, 1]

Question

What would it be a recursive algorithm to get permutations for any list of n elements that might contain or not repeated elements?

For the following 3-element list [1, 1, 2] I would expect the following result:

[1, 1, 2]
[1, 2, 1]
[2, 1, 1]

So far I have the following result:

[1, 1, 2] <- duplicate
[1, 2, 1] <- duplicate
[1, 1, 2]
[1, 2, 1]
[2, 1, 1] <- duplicate
[2, 1, 1]

with algorithm below:

FUNCTION permute(array, nestingLevel) :
    FOR index = nestingLevel TO array size -1
        SWAP array[index] WITH array[nestingLevel]
        CALL permute (array, nestingLevel + 1)
        SWAP array[nestingLevel] WITH array[index]
    END FOR

    IF recursionNestingLevel EQUAL TO array size - 1
        PRINT array
    END IF
END FUNCTION

DEFINE array[] := 1, 1, 2
CALL permute (array, 0)