0981-time-based-key-value-store.rs

use std::collections::HashMap;

struct TimeMap {
    hm: HashMap::<String, Vec<(String, i32)>>
}

impl TimeMap {

    fn new() -> Self {
        Self {
            hm: HashMap::new()
        }
    }
    
    fn set(&mut self, key: String, value: String, timestamp: i32) {
        self.hm.entry(key).or_default().push((value, timestamp));
    }
    
    fn get(&self, key: String, timestamp: i32) -> String {
        let mut res = String::new();
        
        if let Some(t_list) = self.hm.get(&key) {
            let (mut l, mut r) = (0, t_list.len());

            while l < r {
                let m = l + (r - l) / 2;
                if timestamp < t_list[m].1 {
                    r = m;
                } else {
                    res = t_list[m].0.clone();
                    l = m + 1;
                }
            }
        }

        res
    }
}