Codeforces Round 952 (Div 4) | Video Solutions - A to H1 | by Viraj Chandra | TLE Eliminators

[@TLE_Eliminators]

Please fill the feedback form for PCD: forms.gle/qoc6BDkEeCntCncu8

[@shashankvashishtha4454]

ah, finally Viraj sir, he good PCD very very good, please assign viraj sir always or most of the time.

[@anubhavmishra9867]

Best explanation for the problems till now

[@deathigniter2155]

Kya hi pyaara aur bdhia teacher hai.. thank you sir.... baaki sab teachers ko smjhana nahi aata priyansh bhaia.. please let this teacher do all your videos.... he is amazing

[@shreyanshjain1595]

TLE ELIMINATORS IS IMPROVING DAY-BY-DAY CONTESTS -AFTER-CONTESTS KUDOOS TO THE TEAM KEEP IT UP

[@lofibeats2344]

The way you explained g with the exact intuition you had during contest is just awesome. Keep this quality

[@ankitghosh9873]

Intuition + world class explanation ! Please TLE make all the editorials by Viraj and Gaurish,They are LGM at explanation ! other than these two all are newbies . Guys if you agree like the comment so that they can hear asap

[@manpatel9157]

Sir, Please upload Leetcode Weekly Contest 401 Solutions. We're addicted to your explanation🥺🙏

[@NITISHMISHRA-nr8fi]

man this is like so good . these kind of explanation with intution is what makes a difference !

[@TFue01]

loved the explanation of the E question was absolutely on point

[@the_ghost_of_uchiha5939]

Great explanation Sir! 😇 Those who are trying for problem F the working range of r is 1e13 not 1e18.So don't take more than that. Because in worst case : power[i] = 2*1e5 cooldown[i]=1 and mid=(0+1e13)/2 => 1e13/2; Therefore, attack Power at that moment (2*1e5*1e13)/2 ==> 1e18. Therefore range of 'r' more than that won't work.

[@JIGARSINGTHAKOR-yy6qp]

yes i got hacked after contest🥲

[@VirajChandra]

Hi! Yes, you are correct. I have cleared this out in the other comments and also attached the correct submission link.

[@the_ghost_of_uchiha5939]

😇

[@puneet6946]

Great explanation, I've seen a lot of people do this but they all skip some or the other steps but this was just fantastic. I hope you continue the good work 😊

[@pratyushdubey5362]

Thanks for such a detailed explanation.

[@jackma9528]

sir, i'm having an issue, i can't solve div2 problems but i'm not complete newbie, shld i join level2 tle course

[@harshyadav4-yearb.tech.che634]

F is testcse pe nhi chlega.Jab n ki value 2*10^5 ho,saare ai ki value 2*10^5 ho aur saare ci ki value 1 ho. Fir hum log jo sum le rhe hai loop me wo overflow kar jayega. Isliye apne ko loop me hi check karlena chahiye aur jaise hi sum health se bada hota to whi pe break kar dena chahiye.

[@VirajChandra]

Hi, not exactly this, since I already have a check for h health becoming zero. So if everything is 2*10^5 then h becomes zero before going to BS. Correct hack to my solution would be if we give some case where I don’t exhaust h before going to BS. Anyways, hacking is fun! I’ll change the submission link so that we get a better solution.

[@harshyadav4-yearb.tech.che634]

@@VirajChandra okay got it

[@channel-te5vk]

In F . Try setting the high pointer =h *(2e5). This will work. Because worst case scenario is attack is 1 and its turn is 2e5

[@VirajChandra]

A pointer for 10^12 works. Base point, try not to overflow. Had this been python we would have been good enough.

[@channel-te5vk]

@@VirajChandra Yes exactly.

[@AyushGupta-ux4gq]

Thanks bro

[@SubhranilKar-r6u]

@@VirajChandra can you explain why we should take higher limit r = 1e18 ? can't undestand that.

[@RashedunnabiRashed]

Awesome explanation viraj🎉

[@Gyanpapi_]

I did like the way he explained ,super

[@pabitrakb5291]

Thank you for this Great explanation

[@dipanshuraj18]

In 3Q. (Good Prefix) If we take an array 1 2 2 3 then 5≠3 but 2+2=3+1 so it's a good array but it won't be counted according to the given solution.... Please help me out

[@VirajChandra]

Only one element has to be equal to all sum.

[@ishwarreddy8820]

want discussions for every contest

[@SubhranilKar-r6u]

in problem F , why did you take higher limit = 1e18?

[@priyanshubari9685]

great explanation. keep it up!

[@prakashgk-tz3fv]

In question E, k % ( a * b) and k /(a * b)

[@VirajChandra]

Hi! Since side c has to be integer, a*b should fully divide k. Hence k%(a*b). Next, whichever side value you get has to be less than equal to z, since your side c cannot go above z. Hence second condition.

[@prakashgk-tz3fv]

@@VirajChandra Okey sir got it thank you

[@NOWSHINTABASSUM-vg8lx]

aaap best ho jiii.......

[@vickyroy3595]

i too got same intutuion when i look into problem d

[@rituraj6752]

Viraj bhaiya god op

[@001_abhijeetkumar7]

can anyone help me with this, i am using priority queue and getting wrong answer at test case 16 #include using namespace std; int main(){ long long t; cin>>t; vector ans; while(t--){ int h,n; cin>>h>>n; vector damage(n),cooldown(n); for(long long i=0;i>damage[i]; for(long long i=0;i>cooldown[i]; priority_queue pq; for(long long i=0;i

[@VirajChandra]

What is the TC 16?

[@001_abhijeetkumar7]

@@VirajChandra Done, all test cases passed.

[@sanjusabu5488]

@@001_abhijeetkumar7 faced the same problem what the issue?

[@rachakondaeshwar4129]

F is an easy binary search on the answer . Missed it...

[@gigachad2419]

Mine got hacked anyways

[@ramanujangunturu4996]

I did try like that but it didn't work for me though

[@geethakarnati]

Could anyone tell that test case where binary search getting wrong

[@Idk-qg7hb]

@@geethakarnatikyu mc?

[@Idk-qg7hb]

@@geethakarnatihack karega?

[@AyaGamal2010]

Thanks!

[@gnanaprakash-ravi]

Hi Viraj sir. Your vs code sectioning looks awesome. Please teach us how to set it up. Thanks!!

[@VirajChandra]

Sure, I'll try to cover a video on it.

[@kevinjoythomas6528]

good explaination

[@yashupadhyay8909]

how are you able to submit a solution at 5: 38 pm ??

[@VirajChandra]

Which one?

[@akshitpanwar6505]

5:38 pm is according to Moscow time

[@selvaarumugam370]

F will also work on priority queue it passed for me

[@vanshrana7807]

+1

[@VirajChandra]

That’s great! I mentioned in the video that I did not give alot of thought to the time complexity of a quick implementation in priority queue, so I went ahead with bs. It’s nice that you were able to solve it using priority queue.

[@gigachad2419]

Plz share Submission and Approach

[@gigachad2419]

@@VirajChandra Sir can you please share the approach with priority queues

[@vanshrana7807]

@@gigachad2419 here is the approach just maintain a minheap where you keep the next time when you can use ith attack : #include using namespace std; #define ll long long int #define uni unsigned long long int #define pb(x) push_back(x) #define sz(arr) arr.size() #define ssz(s) s.length() #define nl endl #define read(arr,n) for(ll i=0;i>arr[i] #define srt(arr) sort(arr.begin(),arr.end()) #define srtr(arr) sort(arr.rbegin(),arr.rend()) #define rev(arr) reverse(arr.begin(),arr.end()) #define pi pair #define pl pair #define vi vector #define vll vector #define vuni vector #define vpi vector #define vpl vector #define vii vector #define vlll vector #define mn(a) *min_element(a.begin(),a.end()) #define mx(a) *max_element(a.begin(),a.end()) #define vs vector #define vss vector #define vc vector #define vcc vector #define pre_sum(pre,arr,n) for(i=1;i=0;i--) suf[i]=suf[i+1]+arr[i] const double pie=3.14159265358979323846264338327950; const ll mod=1e9+7; ll gcd(ll a,ll b){ while(a!=0 && b!=0){ if(a>b) a%=b; else b%=a; } if(a==0) return b; return a; } class cmp{ public: bool operator()(pl p1,pl p2){ return p1.first>p2.first; } }; int main() { int t; cin>>t; while(t--){ ll h,n,time=1,p=0; cin>>h>>n; vll a(n),c(n); read(a,n); read(c,n); priority_queue pq; //p.first=time,p.second=index for(ll i=0;i

[@MDHabibur-qk7pj]

r=10^18 dosen't work. use 10^12 instead of 10^18. it works prefect

[@VirajChandra]

Hi! Yes, you are correct. I have cleared this out in the other comments and also attached the correct submission link.

[@Phoenix-dd3kb]

How can I change my c++14 compiler to c++17 I have the required gcc version....Anyone please help

[@TusharKumar-ty8kh]

download from mingw

[@darshanrajpattanaik2154]

Use compiler flag `-std=c++17` while compiling your c++ file without backticks

[@VirajChandra]

Are you using some extension?

[@samsingh43]

use c++20 and precompile. If u want I can give complete setup (my github repo)

[@Phoenix-dd3kb]

@@samsingh43 yes please

[@YashDabhade-cr5my]

Sir, why your solution of F got hacked

[@VirajChandra]

Initially, when I put a check for h being negative, I thought that would suffice the overflow check. But I think we can bypass it, so keeping high as a lower value works now. Solution has been updated.

[@YashDabhade-cr5my]

@@VirajChandra got it