Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2388    Accepted Submission(s): 755 Problem Description As one of the most powerful brushes, zhx is required to give his juniors n problems.zhx t…

zhx and contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 324    Accepted Submission(s): 118 Problem Description As one of the most powerful brushes in the world, zhx usually takes part i…

zhx's contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 851    Accepted Submission(s): 282 Problem Description As one of the most powerful brushes, zhx is required to give his juniors n p…

zhx and contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 455    Accepted Submission(s): 158 Problem Description As one of the most powerful brushes in the world, zhx usually takes part i…

传送门 zhx and contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 145    Accepted Submission(s): 49 Problem Description As one of the most powerful brushes in the world, zhx usually takes part…

传送门 zhx's contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 575    Accepted Submission(s): 181 Problem Description As one of the most powerful brushes, zhx is required to give his juniors…

zhx's contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 3835    Accepted Submission(s): 1255 Problem Description As one of the most powerful brushes, zhx is required to give his juniors n…

[问题描述] 作为史上最强的刷子之一,zhx的老师让他给学弟(mei)们出n道题.zhx认为第i道题的难度就是i.他想要让这些题目排列起来很漂亮. zhx认为一个漂亮的序列{ai}下列两个条件均需满足. 1:a1..ai是单调递减或者单调递增的. 2:ai..an是单调递减或者单调递增的. 他想你告诉他有多少种排列是漂亮的.因为答案很大,所以只需要输出答案模p之后的值. [题解] 对于整段序列单调增或减,就2种情况. 对于先增后减或先减后增:确定一个序列中的最小值(最大值),其他的要么在左边,要…

主题链接: http://acm.hdu.edu.cn/showproblem.php?pid=5187 题意: 从1~n,有多少种排列 使得 a1~ai 满足单调递增或者单调递减. ai~an 满足单调递增或者递减. 非常明显的组合问题 从n个数种选出i个数 剩下的数要满足单调递增或者递减或者递减的规律那么方式唯一 ans = (C(N,0)+C(N,1)+......+C(N,N)) =2^N; 可是这样的情况下 单调递增和单调递减算了两遍  因此要减2 ans = 2^n - 2; 注意n…

Problem Description As one of the most powerful brushes in the world, zhx usually takes part in all kinds of contests. One day, zhx takes part in an contest. He found the contest very easy for him. There are n problems in the contest. He knows that h…