// Check if a string contains consecutive letters that occur only once
fn solve(s: &str) -> bool {
let mut vlist: Vec<char> = s.chars().collect();
vlist.sort();
vlist[..]
.windows(2)
.all(|slice| slice[1] as u8 == slice[0] as u8 + 1)
}
fn main() {
let list = "dabc"; // true
println!("Consecutive letters = {} ", solve(list));
}