题意:一只吸血鬼,有n条路给他走,每次他随机走一条路,每条路有个限制,如果当时这个吸血鬼的攻击力大于等于某个值,那么就会花费t天逃出去,否则,花费1天的时间,并且攻击力增加,问他逃出去的期望 用记忆化搜索做,很好理解. #include<cstdio> #include<iostream> #include<algorithm> #include<cstring> #include<cmath> #include<queue> #in…

题意:有三个骰子,分别有k1,k2,k3个面.每个面值为1--kn每次掷骰子,如果三个面分别为a,b,c则分数置0,否则加上三个骰子的分数之和.当分数大于n时结束.求游戏的期望步数.初始分数为0 链接:点我设dp[i]表示达到i分时到达目标状态的期望,pk为投掷k分的概率,p0为回到0的概率则dp[i]=∑(pk*dp[i+k])+dp[0]*p0+1;都和dp[0]有关系,而且dp[0]就是我们所求,为常数设dp[i]=A[i]*dp[0]+B[i];代入上述方程右边得到:dp[i]=∑(pk…

/* 题目大意:一个n*m的棋盘,每天放一个棋子,每行每列至少有一个棋子时结束.求达到每行每列至少有一个棋子的天数的数学期望. */ #include <iostream> #include <cstdio> #include <cstring> using namespace std; ; double dp[maxn*maxn][maxn][maxn];//放i颗棋子,j行有棋子,k列有棋子 int main() { int t,n,m,i,j,k; scanf(&…

Help Me Escape Time Limit:2000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu Submit Status Practice ZOJ 3640 Appoint description:  System Crawler  (2014-10-22) Description Background     If thou doest well, shalt thou not be accepted? an…

记忆化搜索+概率DP 代码如下: #include<iostream> #include<stdio.h> #include<algorithm> #include<iomanip> #include<cmath> #include<cstring> #include<vector> #define ll __int64 #define pi acos(-1.0) #define MAX 50000 using names…

ZOJ Problem Set - 3822 Domination Time Limit: 8 Seconds      Memory Limit: 131072 KB      Special Judge Edward is the headmaster of Marjar University. He is enthusiastic about chess and often plays chess with his friends. What's more, he bought a lar…

题目链接 参考博客:http://blog.csdn.net/napoleon_acm/article/details/40020297 题意:给定n*m的空棋盘 每一次在上面选择一个空的位置放置一枚棋子,直至每一行每一列都至少有一个棋子,求放置次数的期望 分析: dp[i][j][k] 表示当前用了<=k个chess ,覆盖了i行j列(i*j的格子 每行至少一个,每列至少一个)的概率. dp[i][j][k] 由 dp[i][j][k-1] , dp[i-1][j][k-1], dp[i][j…

题目链接:problemId=5376">http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5376 Edward is the headmaster of Marjar University. He is enthusiastic about chess and often plays chess with his friends. What's more, he bought a large decorative ch…

Domination Time Limit: 8 Seconds      Memory Limit: 131072 KB      Special Judge Edward is the headmaster of Marjar University. He is enthusiastic about chess and often plays chess with his friends. What's more, he bought a large decorative chessboar…

Domination Time Limit: 8 Seconds      Memory Limit: 131072 KB      Special Judge Edward is the headmaster of Marjar University. He is enthusiastic about chess and often plays chess with his friends. What's more, he bought a large decorative chessboar…