Time Based Key-Value Store - Leetcode 981 - Python

0:00 - Read the problem
0:35 - Drawing Explanation
10:30 - Coding Explanation

leetcode 981

#coding #interview #python
Disclosure: Some of the links above may be affiliate links, from which I may earn a small commission.

[halahmilksheikh]

That's so interesting. I didn't know you could find the closest elements this way if the value being searched for doesn't exist in a binary search. Never would have thought of that.

[dianav]

i hated this problem but ur explanation made it less complicated ty

[Dhruvbala]

Nice. And for binary search, could just use right pointer at end of loop -- as that should be the closest value less than target

[adeniyiadeboye]

you are a leetcode legend!...i have watched a couple of your leetcode videos solution

[symbol]

Damn I love this problem and your explaination, thank you man!
Liked again and commenting to support!

[gregorvm]

I was racking my brain with this, didn't read or realize that timestamp was in increasing order, I even implement a sort method in the set so that the array was sorted and the get could be done in log n time, but it wasn't enough some test failed because the time keep running out, then I saw that part of the video expecting some fancy algorithm and was like ._. oh? it's already sorted.

[arkamukherjee]

"Questions to ask in real interviews" - I'd love if you share thoughts on this topic on other problems too! In my experience, it makes a big difference, especially if you can't solve a problem during the interview.

[nishiketsingh]

I got this problem on an interview, if only I was subscribed to you back then.

[dusvn]

This video help me how to find optimal solution.
What is my first solution:
Implement binary search and if value is not finded just go from the end of array, becouse last element is with highest timestamp and check if we can find value < then timestamp.
So now you can see this is time compl of O(n) + O(log n) but O(n) is dominant then time complexity in worst case will be O(n), but in general they will be better but we are looking for worst case.

[baolingchen]

Very concise solution and easy to understand. Thank you!

[iamnoob]

Thanks neetcode, Presentation is really good

[ecepranaykumar]

map<string, vector<pair<string, int>>>mp;

void set(string key, string value, int timestamp) {
mp[key].push_back({value, timestamp});
}

string get(string key, int timestamp) {
auto it=mp[key];
int high=it.size()-1;
int low=0;
string ans="";
while(low<=high)
{
int mid=low+(high-low)/2;

{
ans=it[mid].first;
low=mid+1;
}
else
high=mid-1;
}
return ans;

} getting tle in cpp

[enterprisecloudnative]

i don't understand why the nested part can't be another hashmap like a nested dictionary. in the nested dictionary, timestamp is a string

[Jason-becy]

I really love your videos! Could you upload a video for "843. Guess the Word"? (Top google question)

[qtlmyfj]

yeah i was able to solve this myself once i saw that constraint.

[sidazhong]

I don't wanna abuse Python too much to make everything so easy. lol

[ameynaik]

Nice solution. Can you please do a video on 68. Text Justification from leetcode?

[zenu]

So we assume the input timestamp(s) are always ascending for each key/value? For example they cannot give you ["foo", "bar", 4] then ["foo", "bar", 1]?

[GenevieveKochel]

I'm getting a TLE for this solution

[TheQuancy]

Can anyone explain why we write the binary search that way? I usually have 3 conditions in my binary search