Doremy's IQ || Codeforces Round 808 Div2 Problem C

[@utkarshsharma1185]

Thanks

[@shivam-eh1ew]

Your explanation is pretty straightforward and helpful ... Thanks a lot

[@competitivecoding-newtonsc9601]

Thanks Shivam :)

[@mukundshah1314]

Well Explained

[@competitivecoding-newtonsc9601]

Thanks Mukund

[@ssv6055]

thenks bhaiya!

[@competitivecoding-newtonsc9601]

No worries

[@cristeinfuze8574]

Your editorial helping me alot ..... Thank you !

[@competitivecoding-newtonsc9601]

Appreciate it Cristein :)

[@maheriyajatinbharatbhai3538]

best explanation keep it up 😍😇

[@competitivecoding-newtonsc9601]

Thanks Jatin

[@thamidurandilbandara415]

sir, if i can't solve div2 C should i try to solve div2D so that i become good at div2C or keep practicing div2C?

[@competitivecoding-newtonsc9601]

Keep doing div2c, also this problem was bit harder than a normal div2c so don't worry that much.

[@thamidurandilbandara415]

@@competitivecoding-newtonsc9601 thx

[@AryanGupta-nt5qi]

I have a doubt, that why will long long underflow if the size of bad array is 0. Wouldn't it result in -1 ?

[@competitivecoding-newtonsc9601]

bad.size() returns unsigned int, and if you do -1 it will underflow.

[@AryanGupta-nt5qi]

@@competitivecoding-newtonsc9601 okk thankyou got it

[@AryanGupta-nt5qi]

@@competitivecoding-newtonsc9601 please share your discord link

[@KCOpardeepkumarvishkarma]

why should we type cast v.size() I didn't get it how it will underflow In long long

[@competitivecoding-newtonsc9601]

What I meant to say was not long long, but return type of .size() is unsigned int so -1 will set it to INT_MAX.

[@GAmil890]

Bro how we know wether we take that bad contest or not i cant understand it

[@competitivecoding-newtonsc9601]

You start with IQ q and try to attend all the contest starting from that bad contest. If while attending the contest your IQ drops less than 0, then you were not able to attend all the contests i.e. this bad contest doesn't obey the lemma and isn't part of the optimal solution.

[@GAmil890]

Thx bro I understand it

[@shantanukumar4958]

Can you please make video on problem A of this contest ..i didn't get the concept 🥲

[@competitivecoding-newtonsc9601]

You can join the discord to discuss your doubt, will be hard to make a video now. discord.com/invite/aFBTauq

[@shreyasjain9382]

Going through your solutions after a bad contest really helps man :)

[@competitivecoding-newtonsc9601]

Glad to help

[@kumaramit04-q6c]

I thought of backtracking first, where we can try by selecting or non selecting each of the elements to get the maximum. But i knew it'll give TLE😅

[@competitivecoding-newtonsc9601]

Yeah thats basically bruteforce lol

[@boyidapumohit4715]

@@competitivecoding-newtonsc9601 But I guess we can optimise that with dp? I tried to solve in dp, but couldnot implement in contest, BUt now got to know abut greedy sol\

[@ahmednafis]

@@boyidapumohit4715 dp will have O(n ^2) solution which will also give TLE, also u cant store the DP under given constraints too.

[@ganeshchowdhary3024]

@@boyidapumohit4715 I tried DP knowing that it has a complexity of O(n^2). You have to find the total number of ones possible from each dp state and traverse the dp tree to find where we have taken one or zero. If nn then the answer is all ones. So it is O(n*n)

[@sidharthdhiman4522]

can you chnge your sublime theme if possible , like monokai if possible , in video sometimes not able to see the code clearly

[@competitivecoding-newtonsc9601]

You can see the code from CF profile. I will increase the font going forward.

[@ankitghosh9873]

Understood bt what is lemma!

[@competitivecoding-newtonsc9601]

Lemma is kind of a argument that proves a theorem.

[@amchourasia]

10:50 got to know something that is really important for me

[@competitivecoding-newtonsc9601]

Glad it helped

[@ganeshchowdhary3024]

I think it is good to know both binary search and greedy solutions. Because, sometimes i felt that greedy solutions are quite intuitive and easy to get when compared to isPossible/checker function of binary search.

[@competitivecoding-newtonsc9601]

In this case, greedy was pretty hard to think about in my opinion. Almost all the top coders used binary search.

[@kabboghosh1853]

it's very hard to get this kind of lemma, i don't know how u find such kind of observations

[@competitivecoding-newtonsc9601]

I think what helped is that, if you give a bad contest, it will affect following contests and make some of them bad. So you want to give bad contests as late as possible. And don't be demotivated as this problem was way harder than a standard div2c, many Reds said the same thing so.

[@kabboghosh1853]

@@competitivecoding-newtonsc9601 thanks

[@ganeshchowdhary3024]

@@competitivecoding-newtonsc9601 Maximize - as late as possible, minimize - as early as possible. Makes sense

[@realnight_bot2536]

Wow🆒👍

[@competitivecoding-newtonsc9601]

:)

[@realnight_bot2536]

@@competitivecoding-newtonsc9601 could u please take a session on cf profile review, 🙂just for some advice and fun

[@yourbestie4138]

niceee

[@competitivecoding-newtonsc9601]

Thanks

[@kuldeep-ju7iy]

I have used lower bound but it is giving wa on test 3… I can also show my code can you pliss tell me why it is giving wrong ans… //Think twice code once :)) #include using namespace std; typedef long long ll; #define pb push_back typedef long double ld; //typedef __int128 lll; signed main(){ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); ll tt=1;cin>>tt;string pi = "3.141592653589793238462643383279"; while(tt--){ll n,q;cin>>n>>q;ll arr[n];ll a[n]={0};string s1="";ll b[n]; for(int i=0;i>arr[i];b[i]=arr[i]; }ll p=0; for(int i=0;i=n){u=n-1;} if(n-u>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>............................................ /*ll n,k;cin>>n>>k; if(n%2==0){ if(k%n)cout