# ---
# title: 981. Time Based Key-Value Store
# id: problem981
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: Hash Table, Binary Search
# link: <https://leetcode.com/problems/time-based-key-value-store/description/>
# hidden: true
# ---
# 
# Create a timebased key-value store class `TimeMap`, that supports two
# operations.
# 
# 1\. `set(string key, string value, int timestamp)`
# 
#   * Stores the `key` and `value`, along with the given `timestamp`.
# 
# 2\. `get(string key, int timestamp)`
# 
#   * Returns a value such that `set(key, value, timestamp_prev)` was called previously, with `timestamp_prev <= timestamp`.
#   * If there are multiple such values, it returns the one with the largest `timestamp_prev`.
#   * If there are no values, it returns the empty string (`""`).
# 
# 
# 
# **Example 1:**
# 
#     
#     
#     Input: inputs = ["TimeMap","set","get","get","set","get","get"], inputs = [[],["foo","bar",1],["foo",1],["foo",3],["foo","bar2",4],["foo",4],["foo",5]]
#     Output: [null,null,"bar","bar",null,"bar2","bar2"]
#     Explanation:   
#     TimeMap kv;   
#     kv.set("foo", "bar", 1); // store the key "foo" and value "bar" along with timestamp = 1   
#     kv.get("foo", 1);  // output "bar"   
#     kv.get("foo", 3); // output "bar" since there is no value corresponding to foo at timestamp 3 and timestamp 2, then the only value is at timestamp 1 ie "bar"   
#     kv.set("foo", "bar2", 4);   
#     kv.get("foo", 4); // output "bar2"   
#     kv.get("foo", 5); //output "bar2"   
#     
#     
# 
# **Example 2:**
# 
#     
#     
#     Input: inputs = ["TimeMap","set","set","get","get","get","get","get"], inputs = [[],["love","high",10],["love","low",20],["love",5],["love",10],["love",15],["love",20],["love",25]]
#     Output: [null,null,null,"","high","high","low","low"]
#     
# 
# 
# 
# **Note:**
# 
#   1. All key/value strings are lowercase.
#   2. All key/value strings have length in the range `[1, 100]`
#   3. The `timestamps` for all `TimeMap.set` operations are strictly increasing.
#   4. `1 <= timestamp <= 10^7`
#   5. `TimeMap.set` and `TimeMap.get` functions will be called a total of `120000` times (combined) per test case.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
