why when an Iranian writes a comments you guys gang up on him and give him/her some negative feedbacks and he is right its idiotic why cant you accept the fact that he is right and he didnt say anything to offend any one i know you give me dislikes but can u answer me why?

WHY ALL THIS DOWNVOTES !!! :( READ THIS BUTTHURT OTHER COUNTRIES !

Its the contribution of Indians to every field known to men that makes India one of the greatest country of the world . In the words of other great personalities :

Will Durant, American historian: "India was the motherland of our race, and Sanskrit the mother of Europe's languages: she was the mother of our philosophy; mother, through the Arabs, of much of our mathematics; mother, through the Buddha, of the ideals embodied in Christianity; mother, through the village community, of self-government and democracy. Mother India is in many ways the mother of us all".
Mark Twain, American author: "India is, the cradle of the human race, the birthplace of human speech, the mother of history, the grandmother of legend, and the great grand mother of tradition. Our most valuable and most instructive materials in the history of man are treasured up in India only. "
Albert Einstein, American scientist: "We owe a lot to the Indians, who taught us how to count, without which no worthwhile scientific discovery could have been made. "
Max Mueller, German scholar: If I were asked under what sky the human mind has most fully developed some of its choicest gifts, has most deeply pondered on the greatest problems of life, and has found solutions, I should point to India.
Romain Rolland, French scholar : "If there is one place on the face of earth where all the dreams of living men have found a home from the very earliest days when man began the dream of existence, it is India. "
R.W. emerson, American Author: In the great books of India, an empire spoke to us, nothing small or unworthy, but large, serene, consistent, the voice of an old intelligence, which in another age and climate had pondered and thus disposed of the questions that exercise us.
Hu Shih, former Ambassador of China to USA: "India conquered and dominated China culturally for 20 centuries without ever having to send a single soldier across her border. "
Keith Bellows, National Geographic Society : "There are some parts of the world that, once visited, get into your heart and won't go. For me, India is such a place. When I first visited, I was stunned by the richness of the land, by its lush beauty and exotic architecture, by its ability to overload the senses with the pure, concentrated intensity of its colors, smells, tastes, and sounds... I had been seeing the world in black & white

Some great facts about India: 1)Each and every 28 states and 7 union territories of India, have their own LANGUAGE, CLOTHING, CUISINE and LOOK.

2)India alone has the highest number of languages in the world with more than 300 I guess.

3)In India alone you'll find all types of food ranging from sweetest to most spicy food on Earth. I'm not talking about foreign cuisine or restaurants. Its the local food of different states.

4)On this planet, you will notice that the highest number of religions present, are in India. More than 8-Christianity, Islam, Judaism, Hinduism, Jainism, Sikhism, Zoroastrianism, Buddhism.

After reading all these facts , you might be convinced that India is a great country . If you are , you have clearly misunderstood what makes a country great . Its not the history that makes a country great . India is a barren naked land without its cultures, its colors, its religions. However, as a person cannot be deemed great for the clothes he wears; his shoes or hairstyle or the fragrance he chooses to spray over himself, I doubt if greatness should lie in the clothes of cultures, color or monuments India wears. Not only is such a statement highly propagandist, it deems other nations with perhaps equally diverse cultures, peoples and religions un-great. For greatness is a crown for the elite few.

And for all its culture, its history, its religion, its minarets, its color, India like any other country is made of people. Human beings. Little pink creatures, with dark hearts. This is again not a license to greatness, because every country I know of, is made up of human beings.

The man on the street, the rickshaw puller, the tobacco- paan seller, will easily enter into an animated debate on the issue of India’s greatness. To them, all the corruption, the famines (and the Rs. 3 cheques), the electricity shortages, the broken roads, the stinking sewers, peddled to them by their hindi dailies, are signs of a nation gone to the dogs, faltering and staggering and falling.

But the same paan-wallah, the rickshaw puller, will glue themselves to any available radio set if India is playing hockey/ cricket; will talk in higher, happier tones of Sunita Williams, as if she were their blood sister; and celebrate the Indo-US nuclear deal (without being sure of its meaning). Thus is India great, for its people never give up hope. For all our rot and rust and famine and flood, we never stop believing in the Indian dream. Thus, we call her "Mother India" for its peoples are always expecting.

In the end , its the people of India (except those corrupt politicians) who make this country great .

Was it wrong for you? According to my tests, prediction is 100% correct for this contest:)

did you ever figure this out? also got runtime error on B pretest 5 with python

Cause of your rating ?! you wanna escape from newbie ?! Right ?

When one submits a Wrong solution and think that this was right.....

But after ~25 minutes he found that it was wrong -_-

This round should be unrated :(

Maybe the main reason it's good round for you?

Use counting sort kindof. So you now how much elements you need to xor and how much will remain the same. 24848957

Subtracting what 2 numbers? I still don't know how to easily say if points loss was adjusted.

Thanks! Any solution is better than no solution to me :)

Thanks! Would you mind explaining the proof behind your method?

Sure! O((r-l) log²(something)) = O(10⁵ log²(something)) which, sometimes, gets TLE.

I think you can get O(nlogn) if you use fractional cascading.

Errichto, what did you do to get rid of TLE using segment trees of multisets? I tried to represent the multisets using maps, so we avoid some dynamic allocation, but I still got TLE: 25420160

For the AC (25418820), I had to switch the preorder segment tree to use vectors instead of multisets (the merge sort style segment tree). This makes the segment tree unable to support updates, so I had to use "DSU on tree HLD style" to maintain the set of subsizes of outer vertices.

Not quite, consider n = 8

[8]
[4 0 4]
[2 0 2 0 2 0 2]
[1 0 1 0 1 0 1 0 1 0 1 0 1 0 1] 

Thus 2^3 has 7 0s, so 2^50 Should have 2^50 — 1 zeros.

I did segment tree way, divide left and right, check if the segment falls within range. But something went wrong, and I just couldn't debug it :(

At least I found the mistake now

Just some game theory about NIM.

such unexpectable...

It passed 20 tests !!!

Same here. I was wondering why F is F, cause it seemed to be too easy for one of the hardest problems. Now I see that the trickiest part of the problem was "read the statement carefully and do not forget to handle corner cases" )

...

Problem is as hard as many people are able to solve it (the more people can solve it, the easier the problem).

It does not matter whether you almost solved the problem but you missed a special case or you did not have any idea how to solve it (no partial scores in codeforces — I recommend Hackerrank).

The fact that almost nobody else in the room is not solving it and can't hack the solution, does not matter. You should think of all the cases upfront, before even submitting it.

If you did not think of all the cases, you fail the problem. If it was a full feedback contest, then you would see the results during the contest. I totally do not understand your concerns.