两个二进制串a与b，进行两次段取反操作，使得a变为b，问有多少种方法？ 继续阅读【思维】Flippy Sequence
Marjar Cola is on sale now! In order to attract more customers, Edward, the boss of Marjar Company, decides to launch a promotion: If a customer returns x empty cola bottles or y cola bottle caps to the company, he can get a full bottle of Marjar Cola for free!
Now, Alice has a empty cola bottles and b cola bottle caps, and she wants to drink as many bottles of cola as possible. Do you know how many full bottles of Marjar Cola she can drink?
Note that a bottle of cola consists of one cola bottle and one bottle cap.
There are multiple test cases. The first line of input contains an integer T (1 ≤ T ≤ 100), indicating the number of test cases. For each test case:
The first and only line contains four integers x, y, a, b (1 ≤ x, y, a, b ≤ 100). Their meanings are described above.
For each test case, print one line containing one integer, indicating the number of bottles of cola Alice can drink. If Alice can drink an infinite number of bottles of cola, print “INF” (without the quotes) instead.
1 3 1 1
4 3 6 4
For the second test case, Alice has 6 empty bottles and 4 bottle caps in hand. She can return 4 bottles and 3 caps to the company to get 2 full bottles of cola. Then she will have 4 empty bottles and 3 caps in hand. She can return them to the company again and get another 2 full bottles of cola. This time she has 2 bottles and 2 caps in hand, but they are not enough to make the exchange. So the answer is 4.
It’s Karaoke time! DreamGrid is performing the song Powder Snow in the game King of Karaoke. The song performed by DreamGrid can be considered as an integer sequence , and the standard version of the song can be considered as another integer sequence . The score is the number of integers satisfying and .
As a good tuner, DreamGrid can choose an integer (can be positive, 0, or negative) as his tune and add to every element in . Can you help him maximize his score by choosing a proper tune?
There are multiple test cases. The first line of the input contains an integer (about 100), indicating the number of test cases. For each test case:
The first line contains one integer (), indicating the length of the sequences and .
The second line contains integers (), indicating the song performed by DreamGrid.
The third line contains integers (), indicating the standard version of the song.
It’s guaranteed that at most 5 test cases have .
For each test case output one line containing one integer, indicating the maximum possible score. 继续阅读【STL/思维】King of Karaoke
You are in a reality show, and the show is way too real that they threw into an island. Only two kinds of animals are in the island, the tigers and the deer. Though unfortunate but the truth is that, each day exactly two animals meet each other. So, the outcomes are one of the following
If in some day you are sure that you will not be killed, you leave the island immediately and thus win the reality show. And you can assume that two animals in each day are chosen uniformly at random from the set of living creatures in the island (including you).
Now you want to find the expected probability of you winning the game. Since in outcome (d), you can make your own decision, you want to maximize the probability. 继续阅读【概率期望】Island of Survival
There is an island called PiLiPaLa.In the island there is a wild animal living in it, and you can call them PuPu. PuPu is a kind of special animal, infant PuPus play under the sunshine, and adult PuPus hunt near the seaside. They fell happy every day. 继续阅读【思维/快速幂】PUPU
A cubic number is the result of using a whole number in a multiplication three times. For example,so
is a cubic number. The first few cubic numbers areand . Given an prime number . Check that if
is a difference of two cubic numbers.
InputThe first of input contains an integer
For each test case, a line contains a prime number .OutputFor each test case, output ‘YES’ if given
is a difference of two cubic numbers, or ‘NO’ if not. 继续阅读【数学】A Cubic number and A Cubic Number