time limit per test: 1s
memory limit per test:256MB
The working class person has been given another task by the boss, and this time it's a simple one. The working class person gets a headache when it comes to math, so he wants you to help him solve this problem:
A prime number is a natural number greater thanthat has no divisors other than and itself. Specifically, is not considered a prime number. Twin primes are a pair of prime numbers that differ by . In other words, if is a prime number and is also a prime number, then and are called a pair of twin primes. Now, we randomly select two numbers without replacement from the range to . What is the probability of selecting a pair of twin primes?
The first line contains a positive integer , indicating the number of test cases.
Following that, there are lines, each containing a positive integer , representing the range.
One integer per line, representing the value of the probability modulo .
2 10 12345
644444449 669805489
2 10000000 1234567
83016823 478474895
Consider the first test case in the first set of data: (3,5),(5,7) are twin primes. Therefore, the answer is.
时间限制:1s
内存限制:256MB
打工人又双叒叕被老板派任务了,这次老板给了他一个简单的任务。打工人一看到数学就头疼,所以他想请你来帮他解决这个问题:
质数是指在大于 的自然数之中,除了 和其本身不再有因数的自然数。特别的, 不是质数。孪生质数是指相差为 的质数对,即如果 为质数且 也为质数,则称 和 为一对孪生质数,我们从 到 中不放回地抽取两个数,抽到孪生质数的概率是多少?
第一行一个正整数 ,表示测试组数。
接下来 行,每行一个正整数 表示范围。
每行一个整数,表示概率取模 后的值。
2 10 12345
644444449 669805489
2 10000000 1234567
83016823 478474895
考虑第一组数据中第一个测试用例: (3,5),(5,7) 是孪生质数。所以答案为
难度等级: | 0 |
总通过次数: | 7 |
总提交次数: | 162 |