All combinations of inserting spaces into String

[vladul11]

Hey guys!
If i have for example the string "abcde" and i want to return all the String possibiliets resulted in inserting k spaces ( " " ), what would be a correct approach? Ex:
k=0
abcde
k=1
a bcde
ab cde
abc de
abcd e
k=2
a b cde
a bc de
a bcd e
ab c de
.....
k = length("abcde")-1
a b c d e

Thank you!