303940: CF758F. Geometrical Progression
Memory Limit:256 MB
Time Limit:4 S
Judge Style:Text Compare
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Description
Geometrical Progression
题意翻译
求出长度为 $n$ ,并且所有元素在 [l,r] 范围之内的[等比数列](https://baike.baidu.com/item/%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97/1129457)的个数。 当且仅当数列 $a$ ($a_1,a_2,a_3...a_n$) 与数列 $b$ ($b_1,b_2,b_3...b_n$)中存在 $i$ ,使得 $a_i\not=b_i$ 时,我们认为 $a$ 和 $b$ 是不同的数列。 Translated by [Error_Eric](https://www.luogu.com.cn/user/217300) 。题目描述
For given $ n $ , $ l $ and $ r $ find the number of distinct geometrical progression, each of which contains $ n $ distinct integers not less than $ l $ and not greater than $ r $ . In other words, for each progression the following must hold: $ l<=a_{i}<=r $ and $ a_{i}≠a_{j} $ , where $ a_{1},a_{2},...,a_{n} $ is the geometrical progression, $ 1<=i,j<=n $ and $ i≠j $ . Geometrical progression is a sequence of numbers $ a_{1},a_{2},...,a_{n} $ where each term after first is found by multiplying the previous one by a fixed non-zero number $ d $ called the common ratio. Note that in our task $ d $ may be non-integer. For example in progression $ 4,6,9 $ , common ratio is ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF758F/aca20a9143c643513aefd4868a103ba2e067b031.png). Two progressions $ a_{1},a_{2},...,a_{n} $ and $ b_{1},b_{2},...,b_{n} $ are considered different, if there is such $ i $ ( $ 1<=i<=n $ ) that $ a_{i}≠b_{i} $ .输入输出格式
输入格式
The first and the only line cotains three integers $ n $ , $ l $ and $ r $ ( $ 1<=n<=10^{7},1<=l<=r<=10^{7} $ ).
输出格式
Print the integer $ K $ — is the answer to the problem.
输入输出样例
输入样例 #1
1 1 10
输出样例 #1
10
输入样例 #2
2 6 9
输出样例 #2
12
输入样例 #3
3 1 10
输出样例 #3
8
输入样例 #4
3 3 10
输出样例 #4
2