14. Longest Common Prefix

Find the longest common prefix string amongst an array of strings.

Vertical scan approach:

#![allow(unused)]
fn main() {
pub fn longest_common_prefix(strs: Vec<String>) -> String {
    let first = strs[0].as_bytes();
    for i in 0..first.len() {
        for j in 1..strs.len() {
            let sb = strs[j].as_bytes();
            if i == sb.len() || first[i] != sb[i] {
                return strs[0][..i].to_string();
            }
        }
    }

    strs[0].clone()
}
}

Sort approach (only first/last need comparing after sorting):

#![allow(unused)]
fn main() {
pub fn longest_common_prefix_sorted(strs: Vec<String>) -> String {
    if strs.len() == 1 {
        return strs[0].clone();
    }

    let mut strs = strs;
    strs.sort();

    let first = strs[0].as_bytes();
    let last = strs[strs.len() - 1].as_bytes();
    for i in 0..first.len() {
        if first[i] != last[i] {
            return strs[0][..i].to_string();
        }
    }

    strs[0].clone()
}
}