One lesson I have learned on last Div #3 contest is "avoid using pow() function in C++, it is can lead to Wrong Answer".

I am sharing this with a practical example:

This submission works only if you replace long long p = pow(n1, 3) + pow(mid, 3);

with long long p = n1 * n1 * n1 + mid * mid * mid;

I feel like it is useful to sare it !

Could anyone let me know why this submission doesn't work?

Hi codeforces users,

This is a problem solving training prepared by an Algorithm Engineer at Valeo, Mohamed Ayman. Happy coding!

On November 1st 2017, I was rated 1239 and I registered in Codeforces Round #431 (Div. 2). Being able to solve just one problem, my rating fell to 1233.

Getting closer to my first gray-colored handle, I had a real fear from joining contests anymore.. I don't want to become "Newbie".. never!

On December 2019, and after 2 years of disappointment, I knew about (Div. 3) contests. I really was happy and decided I should come back and give it a try..

Despite being able to solve only 2 problems, the 3rd was hacked and I got the idea of 4 problems.. this really increased my confidence. However, my rate only increased by 22 points.. still slow, but I felt like "seems fine.. but not enough encouraging". Now, after my first (Div. 4) contest after around 5 months of inactivity, my rating jumps by 72!

I am really grateful, and this is really encouraging.. thanks MikeMirzayanov, and tanks for testers! I decided I will never give up.

What does it mean when the verdict of my submission is "Judgement failed"?

It has been 3 years when my journey on codeforces started !
I gained a lot of experience and enjoyed a lot of challenging problems.
In 2018, I am seeking more, and wishing you all great ranking improvements.
Happy New Year for all of you :)

According to this wikipedia link, under the title "Success probability of the contraction algorithm":
Number of possible cuts in a graph is 2^(n-1)-1, while maximum number of minimum cuts is nC2, where n is number of vertices.
My question:
Why number of possible cuts differ from maximum number of minimum cuts? why isn't any cut a (candidate) minimum cut?

It is all about virtual participation in passed contests..
After choosing and submitting the start time, why not enable the registrant to edit that time after registration instead of cancelling it and reattempting to register!!
I imagine it to be something like that..

Hey tourist fans. What is the meaning of this logo being added to a user profile?!

For those beginners who want to go deeply in competitive programming.. those sites would help :)
Choose and GO!
Codeforces
TopCoder
SPOJ
UVA online judge
a2oj online judge with it's leveled ladders
hackerEarth
URI online judge
ACM live archieve

Try to enjoy your few days being a legendary master handled :)

Did this person really come first in the round?!
Did he manage to solve 5 problems in 3 minutes while sitting on the ground?!
Is he/she now proud?!
Is he/she the top? did he/she touch the cloud?!
Did he become a celebrity or was looked for to be found?!
If no, what was this for :)

For those who want to learn more about the main topics of competitive programming, I think you will find this helpful.

What is the most efficient way to convert an integer to a string in C++?

Why isn't there an editorial for Codeforces Round #273 (Div. 2)?!
For those who are able to make one.. please don't hesitate.

It's widely known that in body-effort based activities (football, basketball, ...), the player must do a lot of exercises just before the start of the match in order to get ready, but I'm wondering if it differs when activities are mental-effort based (e.g. chess, coding,...). In other words, before a codeforces round, should I relax, take a nap or try to activate my mind by solving some problems?

I have tried many online judges, but found that codeforces is the best one for those who want to be excellent in competitive programming.
Now, after few months of being a registrant, I became an expert (after being so bad in programming)!!
This progress really impressed me and made me write this message to thank the codeforces team, especially MikeMirzayanov
I will recommend this site for all my friends from now on.

I want to ask two questions regarding the final round of VK cup 2015 that was held on 26/7/2015: First, when will the final standings be shown on codeforces? Second, during the round, why isn't it allowed to show the current standings? (Whenever I try to see them, I find the page blocked)