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Create a timebased key-value store class TimeMap
, that supports two operations.
1. set(string key, string value, int timestamp)
- Stores the
key
andvalue
, along with the giventimestamp
.
2. get(string key, int timestamp)
- Returns a value such that
set(key, value, timestamp_prev)
was called previously, withtimestamp_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 allTimeMap.set
operations are strictly increasing. 1 <= timestamp <= 10^7
TimeMap.set
andTimeMap.get
functions will be called a total of120000
times (combined) per test case.
思路:Python里面用tuple作为bisect的对象
import bisect
class TimeMap:
def __init__(self):
"""
Initialize your data structure here.
"""
self.d={}
def set(self, key, value, timestamp):
if key not in self.d: self.d[key]=[]
self.d[key].append((timestamp,value))
def get(self, key, timestamp):
if key not in self.d: return ''
vs = self.d[key]
idx = bisect.bisect_right(vs, (timestamp, 'z'*101))
return '' if idx==0 else vs[idx-1][1]
# Your TimeMap object will be instantiated and called as such:
# obj = TimeMap()
# obj.set(key,value,timestamp)
# param_2 = obj.get(key,timestamp)