Live Mock DSA | GeeksforGeeks

Key Takeaways

foreign [Music] [Music] [Applause] [Music] hi hi are you sure this course is just for 2499 yes and you know this is the only course with this expertise across the world no way yes way [Music] don't delay enroll now Jake's learning together [Music] hi hi are you sure you can prepare for product based companies through this course yes sitting at home no way yes way don't delay enroll now Geeks learning together yes hey uh what do you mean by a self-paced course well the course material is available in the form of video lectures and there are multiple practice problems that come along as well so you can access all of it anywhere anytime and they are available to you for Lifetime no way oh yes way don't delay and enroll now Geeks learning together hey very good evening everyone welcome to this next session of Life mock DSA interview wherein we conduct interviews with our candidates so this is our next session and let me first introduce myself my name is suniti and I am a mentor here at Geeks for geeks and let me add our today's guest we have Aman and yeah let's get started oh okay just a moment he'll be joining us very soon so till then quickly in the chat section can I know if my voice is clearly Audible foreign for confirming and we will be starting our session very soon and till then I would like to inform you all that if any one of you is interested to take part in these sessions then do fill out the form that is there in the description section of this video so uh let us add our today's guests hi Emma hi I'm an am I Audible [Music] hi uh Aman can you hear me foreign can you hear me like a Queen is going black again and again I don't know or like uh so uh maybe our viewers can help us with this so uh please can uh anyways anyone let us know if there is issue from Aman side or if there is issue from my end okay I guess someone things are fine now uh amen are you able to see the screen and hear my voice all right guys so let's just wait yeah his connection may be poor so let's just wait for few seconds like I am fine okay and how's your connection now I think my call it Wi-Fi got sucks okay no issues all right so um uh can you please quickly introduce yourself definitely hello everyone my name is Aman gangwani and currently I am pursuing my bachelor degree from mundelkan Institute or engineering technology jhansi and I am from my brand electronics and communication engineering currently I am in my third year and uh right right till now I have solved 800 plus problems on different different platforms including lead code geek for geeks and some of my projects which include like the basic landing page over Netflix I've designed that using the tech stack HTML CS in JavaScript and currently I am working on my moon stack project which is actually an e-commerce website and in that part I am integrating both the admin and the user portal like a user can access the website from like ordering and taking something items from the by site and admin can access an admit can access all the users and check all the details of data like I am designing both of them it's a custom bracket okay that's great Aman thanks for the introduction so let's get started uh let me quickly uh explain to you what are we going to do so I will share a dog file link that I have done I have already shared so what we will do is uh I will write the questions in those doc file and then you can explain your pseudo code and you can explain your approach there and once we are sorted in the on that part then we will move to the practice portal of Geeks and you will be coding there all right yes all right so uh can you please share your screen and open the doc file that have been shared okay okay give me a second yeah sure is my screen visible yeah yes your screen is visible uh can you open the door fine okay so uh let us start with our first question and that is even in array of size n containing Elements which represent size of the candles they've been reduced all right one unit one each day all right okay and I mean [Music] let me help you with the test okay so uh the question statement is that an array is given to you all right of size n and there are elements inside it which represents the size of the candles for example here the elements are 1 1 and 2 so it is representing the size of the candles that we have and these candles are getting reduced by one unit each day okay so your task is to find the maximum number of days the room is without Darkness okay so for example say the candle is one one two so on the first day the candle will become zero zero two because uh these two candles will get reduced by one unit right this one one two will become 0 0 1 and then at the end of the like after reducing by one this will be 0 0 1 agree and then on your legs the length will again get reduced by one so it will be zero zero and zero all right so uh for two days you can the room can be without Darkness so our answer will be two all right so that is the problem statement and you can start with your approach oh approach came to my mind like uh like if I'm clear I have been given an size of an elements in an array depending the size of candles and I have to tell the maximum number of days the room will be without Darkness yes yes yes okay yes Okay so can you tell me the constraints now like what will be the constraint of these the size of an array the size of the area for the past six okay and what is the maximum size of candle that can be present uh 10 to the power 6. okay so like a first the fall like Brute Force approach that came to my mind after seeing this question is like that that in every every day one of the the side of candle reduces or every chemical the sizable reducer and uh everyday size will reduce so it means like a at one point the all the candles all the I will become zero and at that point that will be my answer exactly okay so uh I think like uh if I can find the maximum element of an array like the maximum size of a candle from the array so it will be like my answer because uh for that particular day like if I have been given an array like a four three one five and two and if I've been given the array like this so after first day I'm gonna I think you got stuck I think so so hello yes you are audible now my voice yes it is audible now like I was saying like I have taken an example of a iPhone yeah I'm thinking that like I have taken an example of Five Element in an array yes it's like four three one five two so after the first day the size of each candle will be reducer so it will be like three two zero four and uh one okay after second day it will be like a who 1 and the zero will know not matter anything before me so it will be like three and zero after third day it will be like a 1 0 2 and at the end of the fourth day it will be like a zero one and zero at the end of script today like my whole array will become zero yeah yeah it will be like a like I can get an uh pattern from this in my mind for this problem like that the maximum element in the array will be a required answer because the maximum element like the question it is clearly mentioned uh till what much of time my room will have the lighter two it will be the maximum element till the candle size is presenter till that point it will give give the lightness to the rumor at the end of that timer it will become the whole the largest side of the element as it becomes zero it means the com that the room will have complete darkness at that point only that will be my maximum number of days till it will have Darkness all right uh so you will be finding out the max segment inside the array rice yes yes all right so that approach seems pretty fine to me so here's the question link I've shared it in the Dom you can open that and yeah you can start coding there okay okay thank you for like I will declare an Elementor like I will declare an integer representing the maximum number of days it will take and now I will Traverse my whole array is that all for the maximum element present in that same thing oh now I will check out the like I will check all the elements and take out the maximum element in that area it will be like this return and then returning that part I think like this should work fine okay yes yeah you can submit it you can submit it yes yes [Music] okay array okay it's 20 powerful I do of course all right all right great amount that was uh it was on your part and can you tell us the time complexity I mean it is like the time complexity should be because I am traveling the array only oneself and there's no any other Looper so the time complex it should be like Big O of n yeah all right so uh okay space complexity should be bigger of one yeah exactly so yeah that was great and you explained actually in a very good way so that was um great problem solving from your part all right now let us move to our next question so and that question is even an array of n strings you don't know the longest common prefix all right so let me help you with the press in case okay so if the input given to you will say uh n strings are given to you that is these four strings okay and then as you can see in all these four strings what is the longest common substring that we have that is g-e-e all right so g e is going to be our answer for this problem statement so uh is the question statement clear to you yes yeah all right so you can uh explain your approach yes um like I guess d e is common for every element there for every single day array okay like I think it will be like that I will Traverse every Stringer and uh I will save every I will make like I will travel every Indus every string and I will save its uh every surprise copies in a map and I will check this for every different every Stringer and uh after that my map will be sliced with every operation with every sub array present in data and then at the end I will Traverse my map and check out the maximum answer that can be present over there okay once again what are you going to store in your map like in my in my obviously like if the other like if I will give you with a string of Geeks for vehicle so I will personally store G and this count will be one then like I will make a map after like I I'll take a map of string comma enter okay how are you going to how are you going to store a g double e inside the map I mean on what basis are you deciding that like uh I will make a wife of Looper I I'll make a nested Looper in that case a first Loop will be of the element then the string count of the string which is a in this case four so in the first Tracer like uh for the case one and N equal to zero then I will Traverse the array for every like uh like a for this first string it's Geeks for Geeks so I will put a loop for the size of the finger and uh in that loop I will save every element like in the first case it will be g e g then it will be d e then d e e then d e e k and I will state all these strings yes sir okay yeah okay explain like a first of all I will take the state B for X which is the first element of the then uh in that I will put a loop or uh till the string side of the Stinger okay and I will Traverse that in every travel so I will I will first of all declare a string temporarily a temporary string in temporary string I will going on I will go on adding the Elementor of my current Stringer like in the first case when I'm traversing I will add in temp G and in my map I will store Tempo which is counter in my map it will be like that in my map the G will be fun and okay then d e will be one okay okay then d e e will be one and I will maintain this for every Stringer I for in this case I am going to going to do this like a mdek okay I will maintain this type of map for every Stringer like in this case I am looking for B for Geeks so I will do it for every step Stringer and G then g e then g triple E then then d e e k then d e e k s like going on so everywhere inside the map will be one only right I mean how are you going to get values greater than this that's equal to 1. initially my map will be like everything have the value zero okay and after that I will do this operation of a arithmetic operation of plus equal to I this will maintain like this will going on adding the count of every Stringer can you write the pseudo code for this okay and then maybe you can do the dry run so that will make your approach move here this first Loop will be the side of the array and in the next Loop me ant foreign okay I comment here and at that I will save it hello screen is visible can you just scroll up a little bit it is getting hidden by the banner hello yes yes all right so what yes I would like saying yes I would like saying to you like for every string I will go on till it's size up and I maintain a string temporarily in this thing temporary I will save every Instinct user of that current Stringer I got the first I am taking example of like I'm taking an example of a which will be G and uh in the map of G I'll create I will increase it's a value it will be one then for the next just a moment you are doing this 10 plus is equal to array of I and J so what is this exactly actually this array I array I is the first thing like I am accessing the ith string and in the is string I am adjusting the zeroth corrections so in the first case I will be 0 so in the I am assuming that for the array of ith ring it will be Geeks and in going inside the Stringer I am saying for the first character which is G I will introduce in my Tempo and in my map I will make the account of G plus plus basically one and then next case it will be d e then I will increase account of a GE in my mapper going on I'll maintain this for every sub every Stringer of the given array and after that at the end I will Traverse my map and check out the maximum counter of the string within the presenter that will be my answer this is my boot okay I think we need to have a dragon here so maybe let us say uh let us don't have a long input let us say the string is g double e and g double yes and engineering okay so uh can you uh tell us the pride run approach for these three strings okay okay like in this case first of all I will go and put the first link which will be like for this case answer will be yes yes I first of all I will go inside the um my first ring which is GE and my map I will say the MP of the like a NP of the test pleasure between one okay and then I will say like a MP of d e equal to one okay then MP of d e equal to one okay yeah for the next thing I will say if in the next finger the string is b b itself I will say if okay okay I got that then increase that counter okay then let us say p of G is now two yes yes now is two okay so right to the yeah MP of GE will also be two now yeah okay nmp of d e k s will be one it will be like a MP offer g-e-e-sl for that I will say like for the first it's MP of key then three Vee then three d e e I also foreign [Music] the longest Sizer like here the long size for the first is like the answer for first three element is common which is three but I will see the size but the the size will vary now the size will be firstly 3G then g e then d e e I will say for how much my uh what is my maximum maximum answer which is three and with that answer also what is the maximum size I will return the maximum size metal which will be d e e how are you going to check for that thing can you write the code for it okay okay okay then I will definitely greater than maximum then foreign yes yes and uh I am declared I have declare two variables and one should be returning string it will be uh first of all empty and the end Maxine like Maxi will play a role of finding the maximum element in my mapper it will save that part so my maxi after the executing the above Loop will become 3 okay and now I will check in my map I go all the string all the element all the instances of my map which will have the count equal to three only I will check them and then I will put a loop if they are first which is the Stringer and its Sizer is greater than return Sizer then I will update my return in the first case the return size is 0 and the first instance it will come is the so the size is the size of the string G is 1 and is greater than 0 so my return will become d then I will say in my second instance 2 and my return size which I've updated is one so I am saying that two is greater than one to update my return yeah and now I will say GE it's to 3 and is greater than the two which is previously presenter so I will I will make my return three like gee then I will check that there's no instant presenter with have this which has a maximum of this Sizer so I will say the return the final return will be my answer it will be GE okay all right that seems uh good and can you tell me the time of time complexity and space complexity for the port time complexity it will be like a and like n Square because I am traversing the string I am using two nested Looper first Loop for the size of the array second Loop for the uh size of inner string present in the array it will be like a big O of n into the size of the maximum like not maximum side of the string yeah okay you were correct between the size of the maximum string maximum length that we have and the space complexities based on because I am using a map to I can use I can see like uh there's no I can do also unordered map of to I can reduce my space over there so like Big O of n it will be there like it's the go of n yes that time complexity is actually good I mean that is the uh optimal time complexity that we can get uh but maybe you can optimize the space complexity if there is any approach like that for space I can see because like give me a second okay yeah sure foreign ER because for inserting element in ordered mapper it it can take like a pickle foreign no any extra space is used okay like no extra speed like constant space yeah exactly okay okay all right maybe just you know maybe you can try according this question in the portal and maybe while doing that you will get the idea so uh let's do that I will share the link foreign you can just do the copy paste I guess you have already written the code so that will save you some time okay foreign foreign for them [Music] okay I think knowledge completely clear yes like a we can optimize spacer there you go if we can find out the maximum element within the array like what is the maximum height of a Stringer present in Array and uh I should put loop on that part only so I think I can reduce some of some of my spaces it cannot be constantly but uh like before doing that can you please just try uh compiling and executing this code okay okay um foreign [Music] yes okay for customers okay okay return minus one also is not present everything yes that is an edge case that you need to take care of so guilty [Music] like if you'll do it minus one I don't think that is going to help you maybe you can change it yeah returning string is empty or not so if it is empty then in that case you can return minus one I think my Italian returning thing not empty because for this case my turning string is T but just add that snippet you know like if the Turning string is empty if the size is zero then you can return minus one okay okay hmm no one thing that is not empty it's giving tea as you know that's why I have introduced the test case five failing it's Max me foreign because it's common for every Stringer to like g g is gone for every string to the very G for every string g e By this thing is it's common for every string now thank you I am thinking if the string is common for a is this if the string is common then the maximum should be equal to n what is that okay it should be like I am taking the maximum of second so this maximum will be present okay okay is equal to okay you see okay like a this maximum it will it will signify me like a this maximum will signify that the spring is common for every slaver like here if there is d e in this case if there's de is the answer but this d e this the maximum will be four because this d e is 4. okay so this maximum will signify that uh it will be like a the like this maximum should be equal to equal to n it will signify that uh like uh the answer which I am getting like the uh it will be having all the elements here yeah so uh you can append your exactly like see the maximum of all the map can be 3 can be four but let us say if the size of the array is 10 then three or four is not going to work right we need it to be 10. yes so like it will signify me like a like in this case I I will tell you what like what is going on like uh in this case if the string of array is thinner and my maximum is Niner my maximum is three like it means I'm getting a Stringer which is common but is common only for threes but it is common only in three uh string not for the every string of the array like this maximum should be common for uh for each for whole Stringer like the common answer which I am getting would be common for whole Stringer not for only the sub part of stringer you're getting my pointer yeah I'm definitely getting it uh you can proceed with the code and all should work fine yes [Music] time limit exceed I think I have to check I'm like I'm taking for whole thing I I was saying you know I was taking forever yes sir I have to take only for the largest Stringer with it independent answer foreign let me know if you need any hints here okay okay foreign which presenter finished all right uh okay I think uh we have taken quite a long time for this question so let's just help me help so that you know what you can do is maybe you can just check for the smallest string and the largest string yes yes so maybe that can help you like you know you can check with like what is the common characters in the smallest string and the largest that we have like a approach that was coming to my mind I was thinking like I can check the maximum element of the Stringer like in this case in the first it speaks for Geeks so I took maintain the all the actual maintain my string only for this character only only for this string only like uh like a it's the largest so every other every other Stringer can't exceeded them foreign exactly so I thought like I should maintain the map only for this Stringer this largest Stringer and I should compare I should compare then every Stringer like you can uh do it without map as well just compare the number of common characters in the smallest string and the largest string because uh you know uh the yes the least size of the longest common prefix that we can have is the size of the smallest string right yes so you can just compare the size of the smallest string with the size of the largest string so that will help you so that is that you can do for it so you want to try it like I can try it but I haven't doubt in my mind like if I'm only checking the smallest and largest triangle then other strings also I have to check them because if I'll not check them so I'm not sure that uh it will be common for demons or not like I am waiting for the largest finger you can be very sure about it uh like let me explain you like in the example one that is given to you the smallest string that we have is geek largest string that we have is yes so okay so if you are not telling me no like if you will sort it like not the largest string I mentioned after sweating the array you know then after you can compare the first element and the last element okay yes yes yeah the size is not going to help you this after sorting because sorting is in alphabetical order done so that will be of help to you so you can use the Sorting algorithm here that is the first approach that you can do and the second thing that you can do is that um without using map you can let us say if you are iterating for let us say the first longest common prefix that you have taken is Geeks for geeks by default okay so you will move to the next string that is Geeks so what you will do you will uh just maintain a temporary variable K okay and you will keep on incrementing it until and unless the value are coming same say for example in Geeks for gigs and Geeks the value will come same till Geeks okay so you will update your thing so and your new string will be Geeks now okay yes now you will you will move to the the next string which is geek okay and you will be completing yeah so you will be comparing the current string that you have in your answer and geek so after comparing both of them you will get your current answer as geek right yes you can compare and then after comparing them you will get your answer as g double e okay so um and in that case you will not need an or not on map so that can be done all right so um it was all about today's session let us now move to the feedback part so just give me a moment all right so yeah uh based on the session uh first of all let me ask you how much would you rate yourself seven I think I think it will be good okay so the thing is that the first question that was there that was a very basic level question and that was mostly meant to check your logical skills okay because there was uh just a very logical implementation in that question we just needed to find the maximum element okay so that was there to just check your logical ability so you performed it good like on the First Co itself you've got the correct answer so that was there uh and that question the time you took for that question was fair but the time you took for this next question was actually quite enough yes yes yeah yeah exactly so the one suggestion is that if at any point of time you feel that you are taking longer than usual then you must ask the interviewer to provide you with the hints all right or maybe you can ask the interviewer to move to the next question okay like uh there was one question as well that I was planning to go with but as because this question went for too long and then we have a certain time limit on that so that's why we didn't move to that third question but anyways you were able to solve this question okay your approach was correct though it took you some time to get to the correct approach but it's fine at least you were able to get to it so that's what matters at the end and uh then one thing is that uh the biggest plus point about you is that your communication skills are very good throughout the interview you were communicating about each and every thing that you were doing you were able to explain your approach so like you know that is a very good thing about your communication skills are great and your logic part is also great you are able to implement the questions so that is also good thing and uh yeah just one drawback that I mentioned that if you think the question is taking longer then you know maybe you can ask the interviewer so um and also this tcsc all these things were pretty clear to you and you were able to understand what I was saying like when I explained the approach for the second question you were able to grasp it all right so I guess it will be a 8 out of 10 and not seven okay it was a fair enough interview it was a very decent session so uh yeah that is from for the feedback part uh anything else you want to share like a for the second question I was wasting my time in implementation only like I thought like you are not like I can't explain my pointy to you completely like uh like I thought like you were stuck in between like I I've not explained you fairly by like going on that implementation that again and again and uh it took a lot of time no it's fine actually there was a time when I was not able to explain your approach so that's why I asked you to you know write the code and then do the dry run so once you did that then after that your approach became clear to me so uh your approach was good but it's just that as it was taking some little extra time that was required so that's why it didn't get accept but uh the approach was good so uh but you need to you know keep in mind those time complexities and space complexities at the end of the day you know we need to do our solving those constraints so like firstly when I have when I opened the question I firstly take only a Time complexity only like is it possible that my Approach will run or not I thought that it should run but I think it was stuck in between okay okay no issue so the two approaches that I explained to you are they clear like definitely like they were clear the second one approach I was thinking of salty only but I thought like no I should implement this like that uh can it should run out to me all right yes okay okay so that was a very decent session I would say you have a good communication skill you have good problem solving skill all right uh so that are the good things about you so yeah and can you give me a two minute one more time like I want to ask you one thing because I I think that we both belong to a same Branch because my bandra electronics are communication so I want to ask you like uh if I want to get a job in The Fan Company like can you guide me towards that path because our branch is very different to like if there's a guidance can you help me okay yeah like you know uh I think that you know maybe there are uh people who can uh help you better than me like you know for these things so uh you can just uh you know in Geeks for geeks we have like plenty of interview experiences we have uh plenty of questions like you know for the proper company so all these things are there in our portal so maybe you can access it and uh one thing like you know getting job is nowadays especially is quite irrespective of the stream that we are in right I mean you can see you know like even the students from the post streams are getting job in PVCs so that is quite a branch independency has been grown a quite a lot in nowadays so that has nothing to do with that you can just keep on practicing right uh keep on visiting these playlists like there are extremely wonderful playlists for geeks itself and um that is where I have done my preparation as well all right like I used to do those things and you know solving questions there's uh solving questions company wise you know those things help me so you can do that as well and you can get the proper guidance from there as well that that will help you a lot okay ma'am thank you ma'am and thank you for these like uh for already such an event it was like like I have learned a lot from this session thank you thank you so much um we uh like to have you here and we hope that it will help you in your preparation Journey so thanks for joining us thanks all right guys so uh that was our interviewee for this session I hope all of you like the session and As You Are all uh you know uh there was certain things good about our candidate that was he was having a good communication skills and his problem solving skills were also good and then certain things that uh certain things that were not so good was that maybe he actually took some extra time in the second question so he could have avoided it by asking the interviewer for some hints or maybe by asking the interviewer to jump to the next question all right so that's in a nutshell about uh the session and also if any of you is interested to take part in these sessions then uh kindly fill out the form that is there in the description section of this video and then you all will be you know joining us in our next interview sessions so thanks for joining us any feedback any suggestions are most welcomed um it was all about today's session everyone keep practicing keep up the hard work and bye everyone