fn main() {
    println!("Hello, world!");
    let tests = [
        (vec!["flower","flow","flight"], "fl"),
        (vec!["dog","racecar","car"], "")
    ];

    for test in tests {
        println!("{:?} is {} should be {}", test.0,
                 Solution::longest_common_prefix(test.0.iter().map(|s| s.to_string()).collect()),
                 test.1);
    }
}

struct Solution {}
impl Solution {
    pub fn longest_common_prefix(strs: Vec<String>) -> String {
        let mut index = 0;
        let mut c = String::new();
        loop {
            for s in strs {
                let prefix = s.chars().nth(index);
                if prefix.is_none() {return c;}
            }
            break;
        }
        "".to_string()
    }
}