Auto comment: topic has been updated by THE_THUNDERSTORM_BEGINS (previous revision, new revision, compare).

I feel some of the solutioms havent used mod correctly

Like they have done (a * b) mod instead of (a mod * b mod) mod

If this can give some overflow, lets try hacking them ?

Also these:

• 308141875 / EswarIsukapalli, his code looks similar to these ,comments in code look suspicious, used python for B, different template in each problem
• 308154242 / Ali-nuces suspicious code, different template in each problem
• 308141908 / Sonali_Paswan exactly same code with 308151686 (different template in each problem)
• 308138643 / Asif777 looks very similar to 308111016 / ashuupandey (but this may be because the question is too simple, idk)
• 308146366 / Accclone003 EXACTLY SAME with 308141908
• 308149500 / parthmax exactly same with 308141908

awoo

exstream is my new favourite word

Auto comment: topic has been updated by THE_THUNDERSTORM_BEGINS (previous revision, new revision, compare).

cheaters code for C

C?#include <bits/stdc++.h>
using namespace std;
 
void dfs(int node, int parent, vector<vector<int>>& tree, vector<int>& dist) {
    for (int neighbor : tree[node]) {
        if (neighbor != parent) {
            dist[neighbor] = dist[node] + 1;
            dfs(neighbor, node, tree, dist);
        }
    }
}
 
void solve() {
    int n, st, en;
    cin >> n >> st >> en;
    vector<vector<int>> tree(n + 1);
    
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        tree[u].push_back(v);
        tree[v].push_back(u);
    }
    
    vector<int> dist(n + 1, -1);
    dist[en] = 0;
    dfs(en, -1, tree, dist);
    
    vector<int> perm(n);
    iota(perm.begin(), perm.end(), 1);
    sort(perm.begin(), perm.end(), [&](int a, int b) {
        return dist[a] > dist[b];
    });
    
    if (dist[st] == -1) {
        cout << "-1\n";
    } else {
        for (int p : perm) cout << p << " ";
        cout << "\n";
    }
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;
    cin >> t;
    while (t--) solve();
    return 0;
}

heaters code for B

B?#include <iostream>
#include <vector>
#include <set>
#include <cmath>
using namespace std;
 
bool isPerfectSquare(long long x) {
    long long s = sqrt(x);
    return s * s == x;
}
 
void solve() {
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        long long totalSum = (1LL * n * (n + 1)) / 2;
        if (isPerfectSquare(totalSum)) {
            cout << "-1\n";
            continue;
        }
        set<int, greater<int>> available;
        for (int i = 1; i <= n; i++) {
            available.insert(i);
        }
        vector<int> p;
        long long prefixSum = 0;
        while (!available.empty()) {
            for (auto it = available.begin(); it != available.end(); ++it) {
                if (!isPerfectSquare(prefixSum + *it)) {
                    prefixSum += *it;
                    p.push_back(*it);
                    available.erase(it);
                    break;
                }
            }
        }
        for (int num : p) {
            cout << num << " ";
        }
        cout << "\n";
    }
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

I agree, actually, when I try to hack other's D2 solutions , I find many similar codes, because they use actually the same template and hash function. Most of them are Newble or pupil, this is unbelievable.(I'm not arguing that these people can't solve D2, I just think it's unusual for so many people to submit so many similar answers in a very short period of time.)