Live Mock Interview with @Striver | MAANG Format | GeeksforGeeks 

Today, many RU-vidrs are only focused on sharing more materials, without considering how companies are asking questions or how freshers can really face interviews. Great work by Striver and GFG for providing practical advice on these topics.

The very first intuition i got after seeing the question was that , first i will prepare M primes in some array/vector. Then i can relate this qn. to unbounded knapsack problem (coin change problem where I've to find minimum number of denominations to make Target price). Or target sum problem to find minimum number of elements to make target . Striver Dp series helped me alot to think out of the box also ❤️❤️. thanks @striver

Here i can see Arjit is struggling to get approach in the very start that clearly shows a real feel to interview ...a nice video to learn a lot from thank you @striver for such gem content ❤️❤️.....I want to know how you choose interviewee?

First thought comes to mind after seeing this question is Coin Change. 1. Find first 3 primes(precompute primes if given lot of queries) 2. BFS to get minimum primes

Sieve of eratosthenes + dp on subsequences

minimum coin required + seive

after seeing the second test case it was pretty simple to undeerstand that there are so many ways so when many ways comes it comes to recursion and then we can move for dp also

We need more such type of mock interviews

Brute force of this solution that strike in my mind is making a vector to store all the m primes and after that use unbounded knapsack to find minimun number of prime to make n

Show us an interview as well where the candidate barely knows anything...!

For brute force approach we can tell that storing ist M prime no in array then simple do combination sum where duplicacy allowed that is we can use same element again T.c : exponential S.c O(M)

I think what he was talking at the end about functions is "Pure Functions". Changing a global variable from within a function is a "Side effect" and it's a bad practice to do that unless absolutely necessary. Pure functions should not have any side effects and given a set of input you can be rest assured that the output will always be the same no matter how many times the function is called.

Mixture of Sieve and Knapsack.

Clearly understood 💯...How companies approach a fresher

If they're asking this level of questions for an OA. Then I won't even make it to the interviews lol.

Last time I checked this video, I was scared. This time, I'm still scared. Phak, I have made no improvement

i think quetion can be easily solved using lower bound concept. in nlogn complexity.

@striver@GeeksforGeeks if N

Coin Change variation where coins are M, and target sum is N, and how come 5+3+2 is 11 ?

What if we find first M primes using a Sieve, and then use a recursion on that list with a constraint of M[prime] < N ? that would just take around O(n) time asymptotically? (I'm not sure Im solving it as I see the question 1st time so I'll update later). Lets take an example: Say I take N=10 and M=1. So my M list is: M[]={2} //since 1st prime is M Now of course here 10%2 is 0 so it works (we can do 10/2 to see how many 2's we need) For the next problem: N=11 M=3 So my M list is: M[]={2,3,5} //3 primes Here, we can see M[3] < N //and M is strictly increasing list so we don't need to check more We see 11%5 !=0 We store 5 in a list say K. So we subtract 5 from 11 i.e. 6 and call this same function on 6 with M[]={2,3}, and concatenate the output on K[]. so what I mean is we get 5 first, then we send 6, so we have M[]={2,3} so we check 6%3 and its 0 so we do 6/3 to see how many 3's we need. So finally we get {5,3,3} is that correct? lemme check P.S. the answer is 5,3,2 in the doc and it seems my disappointment is immeasurable, and my day is ruined.

Million dollar DSA problem - Given k, X and a stream of numbers , determine the average of the last k numbers , excluding the largest X numbers

Can anyone give a test case where gready fail?

binary search lower bound 1st que

7:33 LOL, sieve of.....what !!? 😂

What about we use bfs algorithm? Like simply store first m primes in a queue and then just simply keep iterating until you get the value

sieve of eratosthenes + dp on subsequences(coin change problem modified)

I think most people puzzled with the solution as it was iterative approach, doing the memoization way would have been easy to absorb

Any similar question to practice ? (Dp + sieves combination)

thanks! lot to learn here even if you get the question by yourself.

25:00

38:30

Can You Add These Questions To GFG, I Have Prepared Solution For Few But Can't Find An Online Judge To Check Them I Don't Wanna See The Solution Mentioned In The Video As I Wanna Approach To Correct Answer Myself. Please Add Them

So inspiring men striver you are really great!!!

Is it possible .. to get the the list or all M primes and thn apply Target sum and count minimum counts

Definitely top notch content

yaar itna time kaha dete hain wo log bas 5-10 min and btw ye question 10 min ka hai baki aap jaisa interviewer milega to badhiya kismat

very useful !

Unbound Knapsack ... Dekhte hi bola 😂😂😂

can we do sieve and binary search on search to get lower bound till n=0 if anyway in mid way lower bound out of sieve return -1

I also solver the question but take an hour 🙁

similar to combination sum

Loved it Sir ❤❤❤

7:35 whaaaat

Store all possible M primes in an array in the sorted order then start subtracting given N from last element of the array e.g. if N=19 is given and M is 3 then arr[]{2,3,5} 19%(last element in arr)= 4 now the main twist comes if I go with second last element then it will give me 1 as remainder which isn't a prime number we cannot add this number in our solution array. so if the remainder is 1 we have to switch to 3rd last element which is 2 : 19/5=3 + (19%5/2)=2= 3+2=5. I've not checked all testcases correct me if I'm wrong.

At 7:34 which thing he mentioned he can use to find first n primes?

i don't get the first question, what does it mean? help?

why he just started with tabulation i.e most optimal approach rather giving bruteforce approach first, at 22:02

2+3+5 is 10 right. Why he told its 11?

This qn is similar to coin change

Why can't we use greedy approach here? Like for N=11 and M=3, I could have started from the biggest prime no. that's gonna be 5 and subtract that value from N and update value of N until I don't get value of N less than the current prime no or value of N==current prime no+1. In that case, I will move towards the smaller prime no and try to do the same thing with that. If N!=0 then we can't make N with the help of first M prime no.

Striver se sikh ke striver ko interview dene ka maza hi alag h😂

❤️❤️

agar esa hota hai to meri job toh lagne se rahi😰😰😭

kabhi kisi ko amazon ko amahzin bolte suna hai

test

his voice was shaking

Step1: Make an array with first M prime numbers Step2: Use unbounded knapsack code: import java.util.*; class Solution { public static int minPrimes(int N, int M) { int[] arr = findPrimes(M); int ans = unbounded_Knapsack(arr, N); return ans; } public static int unbounded_Knapsack(int[] nums, int N) { int len = nums.length; int[][] t = new int[len + 1][N + 1]; for (int i = 0; i

All fake and bogus

How can I get a chance to give a live mock with striver?? @striver @take U forward