Possible bug about skipping elements

[zh217]

I may have misunderstood the intention but in several places the element at index 0 is not taken into account when computing minhashes:

probminhash/src/superminhasher.rs

Line 248 in bc3c74c

for i in 1..nb_elem {

probminhash/src/superminhasher2.rs

Line 250 in bc3c74c

for i in 1..nb_elem {

[jean-pierreBoth]

Thanks. And also in setsketcher. impacts for small sketch slices at low j values, just the opposite of my main use. Will push a fix asap (and make a clippy pass)