problem0981

README

981. Time Based Key-Value Store

Create a time-based 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:

• All key/value strings are lowercase.
• All key/value strings have length in the range [1, 100]
• The timestamps for all TimeMap.set operations are strictly increasing.
• 1 <= timestamp <= 10^7
• TimeMap.set and TimeMap.get functions will be called a total of 120000 times (combined) per test case.

Documentation

Index

• type TimeMap
  • func Constructor() TimeMap
  • func (m TimeMap) Get(key string, timestamp int) string
  • func (m TimeMap) Set(key string, value string, timestamp int)

Types

type TimeMap

type TimeMap map[string][]data

TimeMap is a timebased key-value store

func Constructor

func Constructor() TimeMap

Constructor Initialize your data structure here.

func (TimeMap) Get

func (m TimeMap) Get(key string, timestamp int) string

Get the value of key

func (TimeMap) Set

func (m TimeMap) Set(key string, value string, timestamp int)

Set the key and the value Note 3: The timestamps for all TimeMap.set operations are strictly increasing.