Hey, I'm looking for fellow girl coders to practise and learn together. We will be having a telegram group wherein we'll be discussing our approaches after the contest. I believe we rise by lifting others

Can anyone help me debug why using set gives WA while using vector doesn't ? Here is my Submission: https://codeforces.com/contest/1107/submission/102257173 Here is the problem: https://codeforces.com/contest/1107/problem/C

Can anyone share the links of Indian Youtube channels that post videos on Competitive Programming & Interview Problems?

Hello Everyone, I want to share with you all that I have been using codeforces for a while and find it very useful. But I guess due to my obsession with ratings in the last two consecutive contests I have been losing rating continuously. May be its due to pressure to maintaining the rating. Can anyone tell that is there any extension or tool that hides your title and rating of oneself. So that I can only focus on problems instead of anything else. Anything that hides at what rating and colour you are currently are?

Hello Codeforces, By the end of this year I want to get stable blue(expert). How should I practice? Presently I'm fluctuating in green and don't know how to get out of it. Also would practising on other OJs will be beneficial? I'm determined to achieve blue but don't know how to get ahead. Please help

Can anyone tell me how ratings of problems are calculated after the contest?

Need help with the solution of this problem https://codeforces.com/contest/1392/problem/C How to reach intuitively at the solution mentioned in the editorial?

Can anyone suggest good problems on GCD to practice as this is my most weak topic I think

Hey everyone, I'm planning to solve CSES problem set and for this reason, I'm looking for mates in the upper pupil or specialist range who are also willing to solve. Anyone interested please comment.

I wanted to ask how should one upsolve if one is not able to get the idea from the editorial. Searching through the comments has become very difficult these days as the number of comments are enormous. What are the other ways in which one could upsolve?

Hello Codeforces Community, I'm writing this blog post to share different custom codeforces sites(in a random order) which I came across while using codeforces and are really good in different perspectives and can be used for practice. Thanks to all the creators for these websites.

https://codehunt.cc/

https://contestmania.web.app/

http://codedigger.tech/practice/general/

http://algoshots.herokuapp.com/

http://rudradesai.in/cfviewer/

http://upsolve.rf.gd/

https://competitive.herokuapp.com/

Feel free to mention any other websites in the comments. I will update the blog. Cheers !!

Here is my code https://codeforces.com/contest/681/submission/91075066 for the question https://codeforces.com/problemset/problem/681/C. Can anyone help me that use of which thing is causing the MLE and which data structure should be used to avoid MLE?

Hello everyone, while solving problems the code template I use on codeforces doesn't work on CSES. Can anyone point out what can be done in the template so that it can be used in both places. Here is my template

#include <vector>
#include <list>
#include <map>
#include <climits>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <queue>
#include <unordered_map>
#define fastio        ios_base::sync_with_stdio(false); cin.tie(NULL);
#define ln            cout << endl;
#define vi            vector<int>
#define vll           vector<long long>
#define sortl(vec)    sort(vec.begin(), vec.end());
#define sortr(vec)    sort(vec.rbegin(), vec.rend());
#define forn(i, x, n) for(long long i = x; i < n; i++)
#define revn(i, n, x) for(long long i = n; i >= x; i--)
#define in(vec)       for(auto &it : vec) cin >> it;
#define	out(vec)      for(auto &it : vec) cout << it << " "; ln
#define ll            long long
#define pb            emplace_back
#define mp            make_pair
#define um            unordered_map
#define pii           pair<int, int>
#define pll           pair<ll, ll>
#define ff            first
#define ss            second
#define pi            3.14159265359
#define o(x)          cout << x << endl;
#define all(a)        a.begin(), a.end()
#define sz(a)         (ll)a.size()
#define endl          "\n"
#define CLOCK         cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" secs"<<endl;
using namespace std;

const ll Nfact = 200005;
const ll mod = 1000000007;
const ll Nsieve = 1000005;
//https://codeforces.com/blog/entry/74640?#comment-587521

vector<bool> is_prime(Nsieve, true);
void sieve() {
	is_prime[0] = is_prime[1] = false;
	for (ll i = 2; i * i <= Nsieve; i++) {
		if (is_prime[i]) {
			for (ll j = i * i; j <= Nsieve; j += i)
				is_prime[j] = false;
		}
	}
}

ll bSearch(ll l, ll r, ll x, vll arr) {
	while (l <= r) {
		ll m = l + (r - l) / 2;

		if (arr[m] == x)
			return m;

		if (arr[m] < x)
			l = m + 1;

		else
			r = m - 1;
	}

	return -1;
}
//For printing prime factors of a number
void primeFactors(ll n) {
	while (n % 2 == 0) {
		//cout << 2 << " ";
		n = n / 2;
	}

	for (ll i = 3; i <= sqrt(n); i += 2) {
		while (n % i == 0) {
			//cout << i << " ";
			n = n / i;
		}
	}

	if (n > 2)
		cout << n << " ";
}

ll power(ll x, ll y, ll p) {
	ll res = 1;
	x = x % p;

	while (y > 0) {
		if (y & 1)
			res = (res * x) % p;

		y = y >> 1;
		x = (x * x) % p;
	}
	return res;
}

ll modulo(ll a, ll b) {
	ll c = a % b;
	return (c < 0) ? c + b : c;
}

//Use these functions below only when modulus is involved
ll mul(ll x, ll y) {
	return (x * y) % mod;
}

ll inv(ll x) {
	return power(x, mod - 2, mod);
}

ll divide(ll x, ll y)
{
	return mul(x, inv(y));
}

ll fact[Nfact];
void precalc() { // Call this once in main()
	fact[0] = 1;
	for (ll i = 1; i < Nfact; i++)
		fact[i] = mul(fact[i - 1], i);
}

ll nCr(ll n, ll k) {
	if (n < k)
		return 0;
	return divide(fact[n], mul(fact[k], fact[n - k]));
}
void solve() {
	//[IMPORTANT] Make the indexing 0-based if required.
	ll n;
	cin >> n;
}

int main() {
// in(vec) works for size-defined type vectors

#ifndef ONLINE_JUDGE
	// for getting input from input.txt
	freopen("input1.txt", "r", stdin);
	// for writing output to output.txt
	freopen("output1.txt", "w", stdout);
#endif

	fastio
	ll t;
	cin >> t;
	while (t--) {
		solve();
	}
	CLOCK
	return 0;
}

I'm looking to practice Div2 A and div3 A problems from the previous contests. IS there any website which gives all A problems together

Hello, guys, I need your opinion on which platform is better for practising problems

PLease share your opinions and why do you think so?

Can anyone help me why my code is giving runtime error on cf but works fine on my local machine? Code: https://codeforces.com/contest/1215/submission/89127974 Problem: https://codeforces.com/contest/1215/problem/C Will codeforces compiler give an error if a vector is empty and size function is called on the vector ?

I have seen in many people's code that they use a solve function instead of writing the logic in the main function. What advantage it has over writing the code directly in the main function?

Hello guys, I recently came to know about this fact that in codeforces contests many times I miss on problems which are based on observations, So I had to ask will doing a lot of problems with the tag of constructive algorithms help me in improving my observational skills?

Heys everyone, in what should one do so that he'll able to speedily solve Div2 A, B and C in every contest?

Can anyone tell ideally at least how many questions should one upsolve after the contest so that one continuously improves?

Which codeforces contest are suitable for virtual participation to learn as many standard techniques and algorithms as possible?

Can anyone give their views oh how is this site http://brainstellar.com/?fbclid=IwAR19ux_71mWDJqW0cjKqqDSlUgmkSVDXzsPVT7Tmv7Vy8pxcz3UNdJDjCHw for preparing probability for technical interviews?

Can anyone help me with the detailed solution for the ques https://atcoder.jp/contests/arc061/tasks/arc061_a ?

Hello guys, I'm looking for a mentor (who is quite active on cf). Is anyone willing to mentor? Thanks in advance

Is there any feature in codeforces wherein I can see the list of all virtual contests(not just the recent ones) given by me. Or if there exists any plugin that would also be helpful.