JagguBandar's blog

Invitation to CodeChef Starters 140 (Rated till 5-Stars) — 26th June
By JagguBandar, 6 months ago, In English

We invite you to participate in CodeChef’s Starters140, this Wednesday, 26th June, rated for till 5-Stars(ie. for users with rating < 2200).

Time: 8:00 PM — 10:00 PM IST

Joining us on the problem setting panel are:

Written editorials will be available for all on discuss.codechef.com. Pro users can find the editorials directly on the problem pages after the contest. The video editorials of the problems will be available only to Pro users.

Also, if you have some original and engaging problem ideas, and you’re interested in them being used in CodeChef's contests, you can share them here. Hope to see you participating.

Good Luck!

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6 months ago, # |
← Rev. 2   Vote: I like it -12 Vote: I do not like it

why codechef doesn't conduct regular contest as codeforces atleast twice in a week?

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6 months ago, # |
  Vote: I like it +5 Vote: I do not like it

Codechef blog says Dominater069 is setter but this blog says otherwise

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6 months ago, # |
  Vote: I like it +22 Vote: I do not like it

Anything may change but this line fixed.

By the way, he explains nicely.

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6 months ago, # |
  Vote: I like it +4 Vote: I do not like it
Pro users can find the editorials directly on the problem pages after the contest

Tbh I think having editorial link in problem pages isn't so big a deal that it should be a pro feature, it should be available to everyone.Imagine going to codechef discuss every time to look up for editorial of a problem

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6 months ago, # |
← Rev. 3   Vote: I like it +7 Vote: I do not like it

how almost 600 people can solve 5 problems in div 2, codechef must do something about cheaters,they sucker think they will have good impression in interview, fools dont know they will face equally hard problems

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    6 months ago, # ^ |
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    I was sweating for like half an hour(only I know how I solve that) cause I had to do tree removal somehow, true that cc had to something for them.

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      6 months ago, # ^ |
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      true man ,you have to do question under 1 hour ,otherwise you are cooked

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    6 months ago, # ^ |
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    True Man. By Seeing that Break the string question my mind only says how you do this sh*t in O(N). Nothing coming in the brain

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      6 months ago, # ^ |
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      hashing

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        6 months ago, # ^ |
        ← Rev. 2   Vote: I like it 0 Vote: I do not like it

        Looks like gotta learn & practice Z-Function and String Hashing

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          6 months ago, # ^ |
            Vote: I like it +7 Vote: I do not like it

          I don't know Z-function , actually you can solve almost every problem by hashing which are solvable by Z-function if you know how to do hashing smartly

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6 months ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

Don't Know whether i should be happy that i solved E or sad because it was 2 min late

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6 months ago, # |
  Vote: I like it +23 Vote: I do not like it

I just cannot comprehend how there are 700 ACs on a string hashing problem and about 1700 ACs on a dfs problem while just 1 month ago even the simplest of greedy problems used to get atmost 500 ACs. Recently there have been a lot a channels live streaming contest solutions and today I saw that the guy even solved the last matrix problem which can get someone a good rank even in div1. I guess a region ban is not so far off a solution at this point.

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    6 months ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    every time I solve a problem and look at the solve count , I am like : "Wow people have become so smart these days"(But I guess many of them are cheaters)

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    6 months ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    Well, since Codechef is Indian, a ban on Indian users is not possible.

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    6 months ago, # ^ |
    ← Rev. 3   Vote: I like it +4 Vote: I do not like it

    @authers , I have one suggestion , codechef can hire 2-5 people and manually check all 700 solution ( if i can find similarities within searching of 5 minutes ) if they found similar solution more than 5 times permanat ban that id, and dont allow any id from that ip address

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    6 months ago, # ^ |
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    D was not a dfs problem.. just u need to store edges in adjacency list using sets and solve greedily.

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      6 months ago, # ^ |
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      Can you please tell me how you would print the sequence of nodes removal without a dfs/bfs ?

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        6 months ago, # ^ |
        ← Rev. 4   Vote: I like it +3 Vote: I do not like it

        My Approach: First get all the leaf nodes then store the one with maximum a[i] value and then remove its connection from its parent and if its parent has only one connection after removing then add it to pq.

        Here is my code...

            int n;
    cin >> n;
    vector<int> v(n);
    for (auto &e : v) {
        cin >> e;
    }
    vector<set<int>> gr(n);
    for (int i = 0; i < n - 1; i++) {
        int x, y;
        cin >> x >> y;
        gr[x - 1].insert(y - 1);
        gr[y - 1].insert(x - 1);
    }
    priority_queue<pair<int, int>> qq;
    for (int i = 0; i < n; i++) {
        if (gr[i].size() == 1) {
            qq.push({v[i], i});
        }
    }
    vector<int> res;
    set<int> ress; 
    while (!qq.empty()) {
        auto [wt, x] = qq.top();
        qq.pop();
        if(ress.count(x+1)) continue;
        res.push_back(x + 1);
        ress.insert(x+1);
        int y = *gr[x].begin();
        if (gr[y].count(x)) gr[y].erase(x);
        if (gr[y].size() == 1) qq.push({v[y], y});
    }
    cout << res.size() - 1 << "\n";
    for (int i = 0; i < res.size() - 1; i++) {
        cout << res[i] << " ";
    }
    cout << "\n";
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    6 months ago, # ^ |
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    Yeah,man this is clearly going out-of-hand.codechef caught 700+ people cheating(pretty sure the actual number would be double this),I think the platforms should introduce verification of some kind,so that once an account gets caught,they wont be able to create a new account and reverify it with the same credentials

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6 months ago, # |
  Vote: I like it +7 Vote: I do not like it

I got cooked cuz of D, Solved E but no use. Codechef please weight questions. It doesnt make sense that all questions have same weightage. Even if u solve a harder problem and the other ones solve easier one both are at the same level. Please reward harder solves like codeforces does

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6 months ago, # |
  Vote: I like it 0 Vote: I do not like it

This was a badly made contest. The first 3 problems in div2 had the same diffculty,why? Please keep a difficulty gradient(like there was in the past contest).

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