The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order of the problems. As we know, the arrangement will have a great effect on the result of the contest. For example, it will…

Description The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order of the problems. As we know, the arrangement will have a great effect on the result of the contest. For examp…

The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order of the problems. As we know, the arrangement will have a great effect on the result of the contest. For example, it will…

Problem Arrangement ZOJ - 3777 题目大意:有n道题,第i道题第j个做可以获得Pij的兴趣值,问至少得到m兴趣值的数学期望是多少,如果没有的话就输出No solution. 数学期望很好求,求出符合的方案数与总方案之比就是概率,概率的倒数就是期望.问题在于怎么安排这些题目的做题顺序,如果直接暴力的话,有12!种情况,铁定超时,所以我们可以转换成dp的思想,总共就是12道题,也就212-1种状态,我们枚举每个状态得多少分时的方案数,最终符合的方案数就是dp[212-1]…

Problem Arrangement Time Limit: 2 Seconds      Memory Limit: 65536 KB The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order of the problems. As we know, the arrangement will h…

题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3777 Time Limit: 2 Seconds      Memory Limit: 65536 KB The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order…

Description The 11th Zhejiang Provincial Collegiate Programming Contest is coming! As a problem setter, Edward is going to arrange the order of the problems. As we know, the arrangement will have a great effect on the result of the contest. For examp…

原题:ZOJ 3777  http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3777 题意:给每个题目安排在每个位置的value.有一个程序随机选择安排的顺序,总的value值大于等于m时,就可以接受这个安排.问能够获得一次满足条件的安排的期望次数. 这题不会做,看网上是用状态压缩DP做的. 定义: dp[i][j]为选取了前i行,趣味和为j的方案种数. 由于程序是每次随机选择一个排列,每次的选择之间不影响,而且每次选中的概…

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5264 题意:给出n道题目以及每一道题目不同时间做的兴趣值,让你求出所有做题顺序中兴趣值大于等于m的比例.用一个分数表示. 状压dp. 枚举每一个状态,用二进制表示.dp[i][j]表示第i个题目,兴趣值为j的个数. 转移方程 dp[i|(1<<j)][k+a[num][j]]+=dp[i][k];兴趣值大于m的为 dp[1|(1<<j)][m]+=dp[i][k…

LINK:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3777 题意:有N(\( N <= 12 \))道题,排顺序,当某道题选择了放在第j个位置时,会获得Pij的点数,但其他题目就不能选择j位置了.要求总获得的点数要大于M(\(1 <= M <= 500\)),问在所有方案中选择出合法方案的次数的期望值. 思路:题目要求的期望值,比较简单,就是总方案数和合法方案数的比值.看题目就知道是个DP,重点在于状态设计…