README.md

522. Longest Uncommon Subsequence II

Given an array of strings strs, return the length of the longest uncommon subsequence between them. If the longest uncommon subsequence does not exist, return -1.

An uncommon subsequence between an array of strings is a string that is a subsequence of one string but not the others.

A subsequence of a string s is a string that can be obtained after deleting any number of characters from s.

• For example, "abc" is a subsequence of "aebdc" because you can delete the underlined characters in "aebdc" to get "abc". Other subsequences of "aebdc" include "aebdc", "aeb", and "" (empty string).

Example 1:

Input: strs = ["aba","cdc","eae"]
Output: 3

Example 2:

Input: strs = ["aaa","aaa","aa"]
Output: -1

Constraints:

• 2 <= strs.length <= 50
• 1 <= strs[i].length <= 10
• strs[i] consists of lowercase English letters.

Solutions (Rust)

1. Solution

use std::collections::HashMap;
use std::collections::HashSet;

impl Solution {
    pub fn find_lu_slength(strs: Vec<String>) -> i32 {
        let mut count = HashMap::new();

        for s in &strs {
            let s = s.as_bytes();
            let mut subs = HashSet::new();

            for x in 1..2_i32.pow(s.len() as u32) {
                let mut sub = vec![];

                for i in 0..s.len() {
                    if x & (1 << i) != 0 {
                        sub.push(s[i]);
                    }
                }

                subs.insert(sub);
            }

            for sub in subs.into_iter() {
                *count.entry(sub).or_insert(0) += 1;
            }
        }

        count
            .iter()
            .filter(|&(_, c)| *c == 1)
            .map(|(sub, _)| sub.len() as i32)
            .max()
            .unwrap_or(-1)
    }
}