struct Solution;
impl Solution {
fn is_prev(prev: &str, next: &str) -> bool {
let mut i = 0;
let mut j = 0;
while i < prev.len() {
if prev[i..=i] == next[j..=j] {
i += 1;
j += 1;
} else if i == j {
j += 1;
} else {
return false;
}
}
true
}
fn longest_str_chain(mut words: Vec<String>) -> i32 {
let n = words.len();
let mut v: Vec<i32> = vec![1; n];
let mut res = 1;
words.sort_unstable_by_key(|s| s.len());
for i in 1..n {
let cur = &words[i];
let m = cur.len();
for j in (0..i).rev() {
let l = words[j].len();
if l == m {
continue;
} else if l == m - 1 {
if Self::is_prev(&words[j], &words[i]) {
v[i] = v[j] + 1;
res = i32::max(res, v[i]);
break;
}
} else {
break;
}
}
}
res
}
}
#[test]
fn test() {
let words: Vec<String> = vec_string!["a", "b", "ba", "bca", "bda", "bdca"];
assert_eq!(Solution::longest_str_chain(words), 4);
let words: Vec<String> = vec_string![
"ksqvsyq",
"ks",
"kss",
"czvh",
"zczpzvdhx",
"zczpzvh",
"zczpzvhx",
"zcpzvh",
"zczvh",
"gr",
"grukmj",
"ksqvsq",
"gruj",
"kssq",
"ksqsq",
"grukkmj",
"grukj",
"zczpzfvdhx",
"gru"
];
assert_eq!(Solution::longest_str_chain(words), 7);
}