Big thanks to Tim for being willing to do this coding interview in front of all of KZfaq! Check out the video we did on his channel here kzfaq.info/get/bejne/ptB6qNSIvNepdH0.html, and here are a few timestamps for the coding interview: 0:00 - Introduction 2:09 - Intro chat 3:03 - Interview starts 49:12 - Interview ends (overtime starts) 52:58 - Debrief 59:40 - Conclusion

This dude is being interviewed for a job at Google and is using Firefox for the interview! What an absolut madlad!

I feel like I would instantly forget everything I ever learned about coding in an interview like this :/

Microsoft Word is my favorite IDE

Why am I watching this I’m a biology student

Thanks again for doing the interview Clement! I learned a lot and got some great practice. Hope everyone enjoyed :)

Friend: What do you watch in your spare time? Me: It's complicated

Just tell me when you want to have the meeting and I'll adjust my schedule....

For 19 years old, he did really well. At 19, I was just learning basic programming principles. Didn't even have any concept of time or space complexity yet. Good job.

People: If you dont watch movies or shows, what do you watch? Me: Google coding interviews

Ive been told these interviews are: 30% - can you solve this problem in code 70% - how does the candidate problem solve, what is their personally under pressure, can they catch their own mistakes.

I have to say, this video may have helped me get a job at Microsoft. I always froze at the technical interviews focusing SO much on solving the problem mentally, but seeing how Tim takes the time to explain his thought process and then write out his plan, then solve it, I tried that myself and got far more positive reactions even when I wasn't able to compile the code in time. It goes to show, Interviewing is a skill that can be learned and this video is mega useful for learning what people are looking for.

I’m a CS student and I’m struggling… But honestly it’s validating to stumble upon these videos and watch them around every six months as the coding jargon gradually becomes an intelligible language that makes sense. It’s honestly quite beautiful.

Those mock interview are the best thing ever. So useful. Keep up the great work Clement!

Great Channel. What I appreciate in your "interview" videos is the fact that you concentrate a lot on the interaction between interviewer and interviewee. Making clear the problem is a huge factor, there actually you get your answers for your solution. I hope all the students that are looking for an internship are watching this. Wish you good luck with the channel, very good content!

And then there’s me getting an error in my hello world program 🤣😅

"Military time" aka the time the rest of the world uses.

1 year ago when I saw this video, I thought this is way above my head. But now I feel this is so simple and I can spot that logic just on seeing the question. The reason for this is practice, it brings u the confidence that u need to move ahead.

Me in 58 minutes Printf; ("hello)

Well my self esteem has been destroyed

wow! I was so excited to resolve this exercise by my own skills, this guy really good

“That’ll append our pointers” Huzzah! A man of culture

I really love this video. It is very informative. I also want to say that Tim did so well in nailing the framework of the solution to the problem and finally writing such a code not too complex to understand.

What a great problem. I'm going to try to do this in one pass by starting with the person with the earliest start time and then track gap time based on the meeting starts and ends without any internal loops. It was very helpful listening to your discussion/feedback. Algoexpert sounds like something I need to try out.

I'm a fan of this two guy . I've been following this channel and also tim

now tim works in microsoft few years later tim : microsoft coding interview with bois

Amazing video, really gives a reliable picture of what an interview is all about. I actually paused it and came out with a nice solution to the first approach that Tim suggested. I think that by holding the numbers in a class containing the start/end times (instead of [0] and [1] indexes), and adding some useful functions to it like a function that takes another object of that class and gives you the overlapping time between them as an object of that class - the code may become much more elegant and readable (I believe even more readable than the single list approach) but naturally much more difficult to do in 45 minutes time unless if you're very used to creating those handy classes naturally. Thanks so much for uploading it, and good luck Tim!

I would say this is the most realistic coding interview in this channel. Others, who came here (like William lin) were godlike in their algorithm and coding skills, Tim certainly is more relatable candidate. I am about his age, and studying in college (in 2020) too. So, awesome experience for me

Hello Clément thanks for sharing those tricks with us, and please keep making free content like this you are a source of inspiration for many college students and developers in many countries.

Title: "Interview with a college student" TIM is no ordinary college student, don't believe me watch his videos. He teaches much better than my prof!!

What a great video Clement and Tim you've got a lot of courage tackling this while videotaping. Great job...

This reminds me (just a tiny bit) of the interview I've got for a full time job. Except it was a general culture thingy instead of an actual algorithm to create. That was a great video ! :)

20:40 That moment of realisation.

As a prospective high school student looking into CS, I really enjoyed this. I think problem solving like this is just so interesting and I could imagine myself pursuing a job that's problem solving heavy like this. Thank you very much, great content!

I can confirm CS students deal with a lot of of calendar and comparison problems lol

I've landed the job I wanted but I still get super stressed seeing videos like this.

Was subscribed to Tim long time ago happy to see a collab between you ✌🏻☮️

I'm always impressed by coders intuition, i've tried coding several times and it never quite clicks with me. Props to everyone out there who has the skills for it.

One note, as you are going through your logic I would recommend as I like to do, building out a scaffold with comments documenting your "thinking out loud" in sudo logic. This way when you get into code mode, it is much easier to retrace your steps. Food for thought! Great video! It was super interesting learning how Google does it.

Thank you for this information. Every time I thought I understood how to solve the issue. I was wrong again. But I'm glad I got to learn how to go about a situation like this. Thank you guys for taking your time to do this. Have a wonderful afternoon.

I'm going to follow along and pause the video before Tim works on an answer and see how I solve it vs how he did and how long it takes me. Thanks for putting out this content, it is very helpful!!

I feel stressed watching this LOL

Good job Tim and good luck on your future interviews!

This is so fun!! Wish there would be more mock interviews!

how i'd do it: 1. create list of meeting segments with length = meeting time from max(start_times) to min(end_times) 2. start on list 1, cut segments from available list that fall within each unavailable segment 3. repeat for n 4. create available meeting times from joinable meeting segments unless this was server side work in which case i would just redo the oracle so that it could all be done in sql

1st function: find the possible start times and durations for each person based on their schedule and limitation (working day duration etc) 2nd function: find values within the array of starting point of a person falls between starting point plus duration of the meeting (30 min) of the second person starting point and endpoints of second person is greater then first person

i love clement's smile of like proudness when tim get's on the right track its fckn adorable

Loved this video, guys. Great work and GOOD LUCK Tim!

Interesting question. I am happy to see something different! I am sick of seeing recursion questions. Took maybe 1.5 hours around 100 lines of code used c#. I actually ended up doing what Tim wanted to do originally before you changed his mind. I found it more logical as a human to take this approach! You find the available time with both schedules (inclusive of the day start and end boundaries). These results are passed into a method that finds overlapping available time of the schedules. The overlapping spare times are compared with the meeting length requirements to produce the suggested time slots. Highly re-usable and writing it like this I can compare more than 2 schedules for availability (Even could specify who can and cannot make it during a time slot).

I think it is funny that the GOOGLE interview is on Linux on firefox and the headphone he is wearing are Apple Airpods

Wow, it's a nice example of coding interview. Recently I've got a invitation of Google foobar challenge while I was working as a Internship, and your videos are really helpful. I hope I can make it through the interview!

I paused this video as soon as you asked him the question and although it took me a while, I managed to solve it. It's funny, I spent ages trying to figure it out in code, then I just drew it out on paint and solved it in a few minutes, then just had to transfer it into code, which was much easier after solving it by drawing it. I'm loving these problems, I think you're getting me addicted to them. Every single video of yours now I'm pausing and doing them. They are really fun questions!

At the beginning i thought, what the hell, isn't this really simple? But to see Tim struggle made me actually think, maybe it's not that easy.

I have an Interview coming up for the Google internship. This is really going to help. Thanks man love the channel

Dang as I was watching this I had that thought right before you said it. He should merge to one list first. So much easier watching a coding interview than it is doing one. This is a great video.

That was so great it gave me confidence to be confident when im u0 for my interviews

Quick useful info for comparing time strings when it is in military format, there is no need to convert the string into hours and minutes, one can actually just compare the two strings with normal string comparison operators and the result would be as expected.

Easy looking questions with deep algorithms inside.

thank you Clément good job and continue to do this kind of video :) !!

This is great man, I definitely got down the coding but the on the fly type of interview can be very scary. I have to keep coding and learning to be the very best I can be.

me after this interview printf("die");

I am currently having an interview. This was just what I needed!

Loved the session, an insightful one. Please continue. ❤️

randomly saw your vid and i really liked it a lot! subscribed you both

@Clement your mock interview videos are awesome and we love it and we want to see more of it, just a suggestion that you can pick your top performers from AlgoExpert and interview them on KZfaq. I'd love to see this on KZfaq and I'm sure people would too :-)

I would do it actually a little different: First find the maximum day starting boundary. In this case person 2. Set currentTime to this day boundary From there 1. go to other persons calender 2. check if they have time : (find first meeting ending over your current time. see if according starting time is less then current time) a if they have time a1 get from each calendar the lowest starting time of a meeting >= current time (if no meeting get day end boundary) a2 select the minimum of both as currentEndTime a3 add element currentTime, currentEndTime to available time frames a4 set currentTime = endTime of meeting which started earlier and repeat from 1 b if they have no time go to ending of the meeting currently in and repeat from 1 3. elimate timeframes less then needed time

Yet another great video from Clement. I've already purchased both agoexpert and systemexpert and the ROI has been over expectation thus far. here is my approach to the problem in the video. Personally took me about a year to learn stuff by myself, with stuffs like codewars, kaggle and recently algoexpert. The algoexpert data structure crash course is crucial, I recommend people to watch them everyday until they finally grasp the ideas. I don't have great work ethics or talented at all, and have been playing video games consistently, but as I combined watching the videos and solving algoexpert and problems on codewars, I've been able to progress, and progress is everything. Even the easy problems on algoexpert have been quite hard for someone without the basics of data structures like me, and watching the crash course as well as doing related codewar problems has been TREMENDOUS (codeforces is just way too hard to be honest). I truly believe that everyone with interest in programming should use algoexpert and watch clement youtube videos, and codewars DOES help a lot imo. Here is the approach I would take for the problem in the video (I personally think this problem is probably not that difficult, because i have hardly been able to solve problems on codewars and algoexpert on paper without throwing a lot of stuff at the wall, and the problem clement gave errichto is just... impossible for me). Also if you're a newbie that have been learning python and wanting to learn js (like me), algoexpert and codewars is really the way to go! # add a 1 for each time block of 1st person, and a 2 for each of the 2nd person, for easy comparison person1 = [[10:20,12:15,1],[12:20,14:15,1],etc] person2 = [[11:20,12:15,2],[13:20,14:15,2],etc] full_list = combine the 2 lists [[10:20,12:15,1],[11:20,12:15,2],etc] convert all time into int like ([1020,1215],[1120,1215]) (easy) result = [] i = 0 while i full_list[i+1][0] and full_list[i][2] != full_list[i+1][2] : # if one is 1 and the other is 2 then the 2 time blocks belong to 2 different people curr_list = full_list[i] + full_list[i+1] #all 4 items of the 2 time blocks considered sort curr_list result.append(curr_list[1],curr_list[2]) #the middle 2 elements of curr_list automatically becomes the result regardless i += 1 merge overlapping items in result list and return result.

You just need to take the earliest start time of a meeting and merge it with the latest start time of a meeting (for both calenders) whenever the two calenders clash at any time. 30 minute slots can be created within the inital bounds for whenever the calenders do not clash.

When you have been working as a developer for e while and see and student cracking hard questions ....

Here's my take on this problem: - Convert the times into integers (minutes, so 2:00 becomes 120) - Calculate the free time (pairs of times just like shown in video) each person has - Make a bit representation of each minute in a day (24*60 bits), if that person has free time in that minute, set that bit to 1, 0 otherwise - Do an AND operation between the bit representations of free time of every person (joining everyone's free time) - Convert that bit representation back to pairs of times. If the time range is greater than 30 minutes, then accept that pair - Profit You can implement that with constant extra space (if you needed to find availability of 3 or more people at the same time), and time complexity is O(n + m): N is for number of calendars being read (2 in that case) and M is the total number of existing meetings

Good job, Tim! wish you the best!

Thank you for created a video as reference. I learned something new to day :)

Clem, please write the full question statement at the beginning so we could try to answer the question more easily.

We had this question as an assignment during our second programming course in comp sci & software engineering :D

Thank you Clément ! This is valuable content!

Im glad i could keep up. It would take me a little longer to formulate that solution, but remember once a solution is thought up, putting it in code is much much easier

I feel like Google would benefit from just creating their own collaborative coding environment as a replacement for Google Docs in this situation

I think I will forget everything when I get to interview🤣🤣and Here am I who want to work in google but doesn't even know how to print a simple pattern😭😭😭

when comparing 2 blocks , get the max start time, compare it to the min end time and check if there's enough to have a meeting, if there's enough to have a meeting, add the array of max start time to min end time to the output.

Hey it's Tech With Tim! I'm really looking forward to this one.

The collab i was waiting for!!!How did you read my mind Clement???

Hello everyone! I came across this video today and found the problem very interesting! So what I decided to do, was pause the video after Clement gave Tim the sample input/output and coded it myself (to skip to the point, I attached my Java solution below)! I did everything in a google doc and it took me 45 minutes to write the solution. Once I had written the solution, however, I wanted to check my answer! Thus I moved everything over to my IDE and changed the auto-capitalization from google doc and other errors such as me missing parenthesis and such. But voila! Once I fixed all of the general typing/spelling errors, I ran my code and it succeeded! It produced the same output as the sample output given in the video. I thought that some of you may be interested in seeing a working solution, so here I am providing mine! I wrote my solution in Java and here is the google doc link of the cleaned code. Also, in case you were wondering, I wrote the documentation as I was solving the problem. I did not go back afterward and add the comments. Enjoy! This was an awesome problem to solve! docs.google.com/document/d/1O9oAP24bnS5T4uoVxjcJL7CPtHxjKWalXwen_VVeDRY/edit?usp=sharing P.S. I'm a junior at the University of Washington, double majoring in Computer Science and Comprehensive Physics, just incase you we're wondering what my background is :)

Great video! I found coming out with a logical solution is not that hard but the coding, oh boy as u mentioned its quite a headache due to the fact that we presented with quite a lot of information and one is under the pressure of the interview.

honestly i would rather have 15 mins alone in my head to solve a problem than an hour where i cant be silent for more than 10 seconds.. respect for this guy.

The whole interview you were staring at his algorithm while tossing your head around.

interview: "write me an algorithm to count the number of times I nod in this video"

Thanks for the video! I came up with the same original solution that Tim did and your approach was much simpler. I was wondering if you had any advice on coming up with the simplest approach to solving a problem? That to me seems like one of the most important questions, because you save on code complexity and therefore modularity/maintainability and even on how quickly you can come up with the solution. So do you have any advice on maybe a mindset (eg asking myself "How can I do this in the easiest way?" or something along those lines) you use to approach problems and find simple, sensical approaches?

Only having listened to the explanation so far and not the implementation required, this very much reminds me of an in band list approach to a memory allocator. After having seen the sample input/output it reminds of comparing posting lists in boolean retrieval. I would start at the beginning of the earliest bound given and try to find the first block available, then cycle through the other person's calendar up to a point equal, schedule, or up until the earliest past the original available block and then switch back again etc.

This problem can be solved very easy in O(n), just create a bool array of 24*60 if the meetings can be scheduled at every minute, or only 24*2 if the time blocks are 30 minutes, iterate through the calendars and convert the starting and the end points to int and mark all the values as 1. After make a for loop starting from max(boundaries_person1_start, boundaries_person2_start) until min(boundaries_person1_end, boundaries_person2_end) and append to the solution list all the free sequences.

He mentions his OCD will kick in, and then he put the available time of person2 in the first place, available time of person1 in second place, and in one set he uses double quotes and in another one he doesn't...

Best part was them using Apple headphones😀Do. Appreciate the effort here, to boldly go where not may googlians has gone before. Thanks for sharing and helping future candidates. Love googles approach to hire great problem solvers. 👍

He is hired!!! I almost burnt dinner, trying to watch this until the end. At least I found a new KZfaqr to watch :)

There's not a single video that doesn't make me feel to destroy that Like button ❤❤

I forgot how to breath during this interview 😂

I know this video is old but I found a beautiful solution and I couldn't find any comment showcasing it so I thought I might aswell do so. The algoritm starts by creating 2 arrays (one for each person) that represent the free blocks of time throughout the day. We don't need the elements of the arrays to be pairs of times but rather we can create our own data type that represents a given time and wether or not it is the start or end of a free block (for example time=13:00 start=true). For example if lets say one person is free 12:00-13:30, instead of storing the pair[12:00, 13:30] as an element in the persons "freetime-array" we could store the 2 elements e={time=12:00, start=true} and e2={time=13:30, start=false}. We then sort the array in increasing order with respect to the time variable and get a useful way to represent the "freetime-array". We then create a third array that consists of all elements from both of the previously described arrays (both of those are the same btw, just for the two different people). If we sort the third array, once again increasing order according to time, we get something wonderful. What we have done I basically sort of merged together both persons blocks of free time. Lets call this third array a3. Now comes the clever step. We will look for indices j such that a3[j].start and !a3[j+1].start. The time in-between a3[j].time and a3[j+1].time will be time where both people are free. Its easy to verify this (tip: there are basically 2 different cases. Either both the element at j and j+1 come from the same persons free time-array or they don't)! A little harder to verify is that checking for all possible j:s will give us all such interval where both people are free but tbh its pretty straight forward aswell. Yeah so thats basically it

Noticing the time outside the shift is just a meeting really cleans things up. The other thing, if you know what calendar each time belongs to and whether it is a start or end time, you can line each individual time up in an array and loop through 1 time using 2 booleans for availability status of each person.

Having my video call google interview in two days and this helped me get a good insight into how it's like. THANKS!

Google DOCS is my ide starting today.

Big thanks to you , because of you I again got motivated about programming

Great vid, enjoyed the watch.