Codeforces Round 723 (Div 2) | Bugaboos A to D Solutions

[@utkarshgupta9858]

Use invite code HEALTHYUG to watch Modular Arithmetic(for B): unacademy.com/course/modular-arithmetic-operations-under-mod-in-detail/VPR5UIUA Segment Tree (for C2 and D): unacademy.com/a/free-course-on-segment-trees-new

[@mistake10449]

thanks a lot bhaiya mujhe to pehchana hi hoga (unacademy class reference)

[@siddhantkhare1659]

I ruined C :(

[@utkarshgupta9858]

@@mistake10449 yup remember you from class

[@arnab4151]

@@utkarshgupta9858 Hey, the modular arithmetic link isn't working

[@Abhishek-fo3fc]

@@arnab4151 yeah true

[@siddhantkhare1659]

Congrats on Becoming Uber SWE Intern

[@ptiwari1882]

Really? Congrats 🎉🎉

[@dhananjaysharma4379]

just watched ur Modular arithmetic lecture on unacademy, even though I had earlier attended various lectures on the same topic but never got such a crystal clear view of this topic.........It's amazing man.

[@sahil-nz7vk]

For B, this is what I did. I know I only have to check for 11 and 111. Also, since 111 is 10*11+1, every time I subtract 111, n%11 will decrease by 1. So, if n%11 is say x, I need to subtract 111 x times The answer becomes, if n-111*(n%11)>=0, print("YES") else print("NO")

[@meetbrahmbhatt1531]

Bro thanks for giving me an good intuition..was looking for a one liner solution . any tips to solve these types pf questions in contest time quickly?

[@sahil-nz7vk]

@@meetbrahmbhatt1531 usually for these ad hoc questions, you just need a lot of practice to get it quickly. You can practice A B C of contests to get good with ad hoc problems

[@meetbrahmbhatt1531]

@@sahil-nz7vk actually I just started 1.5 months ago and I found this one hard to think on my own thats why was abit upset. Whats your rating on cf?

[@sahil-nz7vk]

@@meetbrahmbhatt1531 Oh, don't get upset if you don't get these problems, with practice you'll get them I'm currently at 1854

[@sudarshankundnani41]

Bhai aapka knowledge to kamal he bhai

[@faisalmahmud9560]

It's super. Bro , please made video after every contest.. i've subscribed while watching your first video from Bangladesh..

[@orzAR26]

Waited badly❤️❤️

[@manthanvats9809]

@Utkarsh Gupta how you parse testcases in sublime text, I use Competitive Companion and FastOlympicCodingHook but after new update of sublime text it is not working.... Please tell how you parse testcases and which plugin you use.. please..

[@swayamsidhant2318]

Bhai b me tumne kya socha . I mean how did you get the logic so fast?

[@johnmcworth5855]

That's why he is red coder.

[@unanimousdisclosed7482]

Don't ask the same stupid question, again and again, look at his practice.

[@ApoorvaRajBhadani]

B jisko turant click Kiya uske liye easy tha Baaki isme kuch ds algo nhi lagana tha

[@emurarryreddy476]

Thank you so much... Really hepful...

[@shashibhushanrajput2461]

bhai you were looking dope in the whole video, take care

[@utkarshgupta9858]

lol thanks a lot

[@uditsanghi9794]

Bugaboo ftw

[@EverythingaboutTechPro]

what !!!!!! C was not dp ! I am so dumb

[@madhavsinghal6230]

It can also be solved using DP

[@siddhantkhare1659]

@@madhavsinghal6230 how bro?

[@johnmcworth5855]

@@madhavsinghal6230 I solved it with 2-D dp and dp + bitmasks too. But still it gave TLE.

[@rahulvij696]

only c1 can be done using DP

[@multiplewaya-qk7uq]

#include using namespace std; #define ll long long int int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); ll n; cin>>n; vector A(n); for(ll &a: A) cin>>a; vector dp(n+1 , vector(1, INT_MIN)); for(ll i = 1 ; i

[@udayverma6120]

Hi, I wanted to know if you solved problems on platforms other than codeforces or not? Please reply

[@javitritiwari9538]

Hey can I request a video on collisions in unordered_map , gp_hash_table we can blow them using specific primes (neal's blog on cf) Thanks :)

[@as.if_0077]

the smile at 10:45 🤣🤣🤣

[@janmejaysingh7402]

Easier to do with B with DFS and early pruning. Start DFS with largest number like 111111111

[@yashjain992]

In C you could just use a multiset and remove the top elements when the sum becomes negative.

[@sqarcle]

No I tried that way. The problem is you need your health to be positive at every instance, e.g. it will not work for -1 -1 -1 3

[@sujaykumar7040]

@@sqarcle it will work , whenever the sum becomes -ve we will remove the largest neagtive till now

[@pixmasterstudios5623]

Can't we sort the array and iterate the sum till it becomes 0 and print the index?? I did this but got WA on pretest 2.

[@sujaykumar7040]

@@pixmasterstudios5623 order matters in this question , you have to go from left to right

[@pixmasterstudios5623]

@@sujaykumar7040 oh. Also I tried using Kadane's algorithm but messed it up. Don't mind me I'm a newbie, started this week only 😅

[@biswajitrout4710]

❤️❤️❤️❤️

[@utkarshnimje]

For the C1 problem, IMO if we sort the potions in descending order and start iterating while adding the health until its >=0 and then return the count then this should work but it doesn't can you tell me what went wrong please?

[@auctal4625]

You cant sort the array coz there is resctrictions(you can move only from left to right). You need to maintain the order as it is.

[@utkarshnimje]

@@auctal4625 Ohh so that's why its throwing memory errors😂

[@siddharthsharma9829]

I also did same but its wa. Eg try for 1 -2 200 your answer would be 3 but correct one is 2

[@utkarshnimje]

@@siddharthsharma9829 Yeah, as @Auctal said, we can't sort the array!

[@aakarshitrekhi8071]

I tried c with recursion , but got tle😭

[@uppuabhinav9938]

same

[@pixmasterstudios5623]

I brute forced it only to get WA on pretest 2

[@aadityaupadhyay6264]

C can be solved using heaps easily.

[@maaz3461]

but how will it work as the prob is position dependent (health_at_any_point >= 0)?

[@aniketash4738]

Bro how to master dp bro ? Give tips bro i m absolute beginner in it

[@kashishbansal2651]

you just make everything easy :)

[@PGTECH]

courses link?

[@utkarshgupta9858]

see pinned comment

[@dipjoybasak3156]

Bhai ur second ques logic was cool, I just brute forced for the value of b till 1e7

[@meetshah5003]

Utkarsh bhai discord kab banaoge

[@utkarshgupta9858]

6 months ago...

[@codetocompetectc1810]

Where is the link ???

[@utkarshgupta9858]

see pinned comment

[@aeons0_0]

but how to prove D =-=

[@shadmanahmed9759]

Is university of allahabad is tier 2 or tire 3

[@AllTricksMania]

For what course ?

[@shadmanahmed9759]

@@AllTricksMania Bca and b tech cs

[@AllTricksMania]

@@shadmanahmed9759 no.. go for United College. Best college in Allahabad

[@ashishnegi9663]

@@AllTricksMania MNNIT: Am I a joke to you?

[@BennyJosephPerepogu]

C solution was good