http://codeforces.com/problemset/problem/148/D 题意:w个白b个黑,公主和龙轮流取,公主先取,等概率取到一个.当龙取完后,会等概率跳出一只.(0<=w, b<=1000) #include <bits/stdc++.h> using namespace std; int n, m; const int N=1005; double d[N][N][2]; int main() { scanf("%d%d", &…

D. Bag of mice time limit per test 2 seconds memory limit per test 256 megabytes Promblem description   The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains to watch fairies danci…

D. Bag of mice time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains t…

D. Bag of mice time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains t…

D. Bag of mice time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains t…

题面 这是我做的第一道概率DP题: 做完后发现没有后效性的DP是真的水: 在这里说主要是再捋顺一下思路: 设f[i][j]表示有i只白鼠,j只黑鼠是获胜的概率: 显然:f[i][0]=1; 然后分四种情况: 1.先手刚好拿到白鼠:概率是i/(i+j); 2.先手拿到黑鼠,后手拿到了白鼠:概率为0: 3.先手拿到了黑鼠,后手拿到了也黑鼠,并且跑的是白鼠:概率是::dp[i][j]=j/(i+j)∗(j−1)/(i+j−1)∗i/(i+j−2)∗dp[i−1][j−2]; 4.先手拿到了黑鼠,后手拿…

time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains to watch fairies…

题目链接:http://codeforces.com/problemset/problem/148/D 题意: 一个袋子中有w只白老鼠,b只黑老鼠. 公主和龙轮流从袋子里随机抓一只老鼠出来,不放回,公主先拿. 公主每次抓一只出来.龙每次在抓一只出来之后,会随机有一只老鼠跳出来(被龙吓的了...). 先抓到白老鼠的人赢.若两人最后都没有抓到白老鼠,则龙赢. 问你公主赢的概率. 题解: 表示状态: dp[i][j] = probability to win(当前公主先手,公主赢的概率) i:剩i只白…

题目如下: You have an initial power P, an initial score of 0 points, and a bag of tokens. Each token can be used at most once, has a value token[i], and has potentially two ways to use it. If we have at least token[i] power, we may play the token face up…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 贪心算法 日期 题目地址:https://leetcode.com/problems/bag-of-tokens/description/ 题目描述 You have an initial power P, an initial score of 0 points, and a bag of tokens. Each token can be use…