Hi Codeforces !

Six days ago, I eagerly participated in Codeforces Round 937 (Div. 4), pouring hours of effort into crafting original solutions to the challenging problems presented. Today, to my dismay, I discovered that all my submissions were flagged for plagiarism.

Upon thorough investigation, I found that my code had been marked as plagiarized due to similarities with several other submissions. However, I want to emphasize that I did not resort to any online compiler nor did I copy code from any external source.

These are some points that I want to put forth which I think the readers should know :

• The code to find the factors of a number is easily available online (I didn't use it though as I have appeared in 80+ contest and the idea of finding factors is quite common) Link
• The other solutions use a triple nested loop, to check for the similarities of substring, while my code uses just a double nested loop.Thus the algorithm itself is entirely different.

My code :

for(auto it : factors){
        string check = s.substr(0,it);
        string check2 = s.substr(n - it,it);
        int cnt = 0,cnt2 = 0;
        for(int i = 0  ; i < n ; i ++){
            if(s[i] != check[i % it]) cnt ++;
            if(s[i] != check2[i % it]) cnt2 ++;
        }
 
        if(cnt <= 1 || cnt2 <= 1){
            cout << it <<"\n";
            return;
        }
    }
}

Other codes :

for (int i=0; i<div.size(); i++)
    {
        int len=div[i];
        string check1=s.substr(0,len);
        string check2=s.substr(n-len,len);
        int cnt1=0,cnt2=0;
        for (int j=0; j<n; j+=len)
        {
            for (int k=j; k<j+len; k++)
            {
                if (s[k]!=check1[k%len])
                    cnt1++;
                if (s[k]!=check2[k%len])
                    cnt2++;
            }
        }
        if (cnt1<2 || cnt2<2)
        {
            cout<<len<<endl;
            return;
        }
    }

• Moreover, there was not much logic involved in that block, which could be 'plagiarized'. It just involved equality checking

• I am a specialist (1479) and div 4 contests are unrated for me, so why would I risk plagiarism in an unrated contest

I request MikeMirzayanov and Codeforces team to look into this

This experience has been extremely heartbreaking and saddening. It feels as though all the headwork, dedication, and passion I invested in upskilling myself went in vain.