Tempter of the Bone Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Description The doggie found a bone in an ancient maze, which fascinated him a lot. However, when he picked it up, the maze began to shake, and the doggi…

http://acm.hdu.edu.cn/showproblem.php?pid=1010   //题目链接 http://ycool.com/post/ymsvd2s//一个很好理解剪枝思想的博客 http://blog.csdn.net/chyshnu/article/details/6171758//一个很好举例的博客 Problem Description The doggie found a bone in an ancient maze, which fascinated him…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1010 Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 131057    Accepted Submission(s): 35308 Problem Description The doggie fou…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 102071    Accepted Submission(s): 27649 Problem Description The doggie found a bone in an ancient maze, which fascinated him…

Tempter of the Bone Time Limit: / MS (Java/Others) Memory Limit: / K (Java/Others) Total Submission(s): Accepted Submission(s): Problem Description The doggie found a bone in an ancient maze, which fascinated him a lot. However, when he picked it up,…

本文链接:http://i.cnblogs.com/EditPosts.aspx?postid=5398734 题意: 输入一个 N * M的迷宫,这个迷宫里'S'代表小狗的位置,'X'代表陷阱,‘D’代表门,‘.’代表可行走的地方,小狗每次可以选择往周围的四个方向行走,问这个小狗能否正好T步找到门. 思路: 利用回溯 + 剪枝,这道题剪枝特别重要. 剪枝一: 可以把图看成这样: 1 0 1 0 10 1 0 1 01 0 1 0 10 1 0 1 01 0 1 0 1 则假设从点 a(i +…

小明做了一个很久很久的梦,醒来后他竟发现自己和朋友在一个摇摇欲坠的大棋盘上,他们必须得想尽一切办法逃离这里.经过长时间的打探,小明发现,自己所在的棋盘格子上有个机关,上面写着“你只有一次机会,出发后t秒大门会为你敞开”,而他自己所在的棋盘是大小为 N*M 的长方形,他可以向上下左右四个方向移动(不可走有障碍点).棋盘中有一扇门.根据机关的提示,小明顿时明白了,他和朋友必须在第 t 秒到门口.而这一切,没有回头路!因为一旦他移动了,他刚才所在的点就会消失,并且他不能在一个点上停留超过一秒,不然格子…

解题思路:相当经典的一题,回溯,具体细节处理见代码. #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; ; ][] = {, , -, , , , , -}; char mapp[maxn][maxn]; int n, m, t, flag, cnt, si, sj, di, dj; void DFS(int x, int y…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 82702    Accepted Submission(s): 22531 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 58766    Accepted Submission(s): 15983 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 89317    Accepted Submission(s): 24279 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 92175    Accepted Submission(s): 25051 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 125945    Accepted Submission(s): 33969 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 135529    Accepted Submission(s): 36393 Problem Description The doggie found a bone in an ancient maze, which fascinated him…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 146511    Accepted Submission(s): 39059 Problem Description The doggie found a bone in an ancient maze, which fascinated him…

M - Tempter of the Bone Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Description The doggie found a bone in an ancient maze, which fascinated him a lot. However, when he picked it up, the maze began to shake, and the d…

  如果所给的时间(步数) t 小于最短步数path,那么一定走不到. 若满足t>path.但是如果能在恰好 t 步的时候,走到出口处.那么(t-path)必须是二的倍数. 关于第二种方案的解释: 这种方案学名为“奇偶剪枝”.我们已知了最短的步数就是直角三角形的两条直角边,实际上的路径却不一定非要沿着这两条边走的.仔细看看只要是移动方向一直是右.下,那么走到的时候总步数也一定是path的.然而由于墙的存在或许我们不可能一直右.下的走下去.为了避开墙,我们可能会向左走,向上走等等.但为了到达目的地…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 149833    Accepted Submission(s): 39945 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1010 题目大意: 输入 n m t,生成 n*m 矩阵,矩阵元素由 ‘.’ 'S' 'D' 'X' 四类元素组成. S'代表是开始位置: 'D'表示结束位置:'.'表示可以走的路:'X'表示是墙. 问:从‘S’  能否在第 t 步 正好走到 'D'. 解题思路: 平常心态做dfs即可,稍微加个奇偶剪枝,第一次做没经验,做过一次下次就知道怎么做了.最后有代码注释解析. AC Code: #includ…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 94669    Accepted Submission(s): 25669 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

学习链接:http://www.ihypo.net/1554.html https://www.slyar.com/blog/depth-first-search-even-odd-pruning.html http://blog.csdn.net/chyshnu/article/details/6171758 题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1010 题解:刚开始写直接超时,还没学剪枝,奇偶剪枝... 关于奇偶剪枝 首先举个例子,有…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=1010 题目描述:根据地图,'S'为开始位置,'D'为门的位置,' . '为空地,'X'为墙,不能经过,问:在指定的时间,是否能到达'门'的位置.注意:路不可以重复经过,时间也要刚好是 t ,不能少. 思路: 此处不能用BFS,因为时间要恰好为t,还是得用DFS,不过需要剪枝才能过. 奇偶剪枝: 从一个点到达另外一个点的最短路径长度(时间)可以根据两点坐标求出,路径长度(非最短)与最短路径的长度同奇…

<题目链接> 题目大意:一个迷宫,给定一个起点和终点,以及一些障碍物,所有的点走过一次后就不能再走(该点会下陷).现在问你,是否能从起点在时间恰好为t的时候走到终点. 解题分析:本题恰好要在某一时刻到达,所以需要用到可行性剪枝中的奇偶剪枝,如果在某一点,它所剩的步数与到终点的最短距离之差是偶数,说明这种情况有可能恰好在规定时刻到达终点,否则不可能,将其剪去. #include <bits/stdc++.h> using namespace std; ][]; ][]; int n,…

Tempter of the Bone 直接上中文了 Descriptions: 暑假的时候,小明和朋友去迷宫中寻宝.然而,当他拿到宝贝时,迷宫开始剧烈震动,他感到地面正在下沉,他们意识到这是一个陷阱!他们想尽一切办法逃出去.迷宫是一个大小为 N*M 的长方形,迷宫中有一扇门.一开始,门是关着的,他会在第 t 秒的时间打开.因为,小明和朋友必须在第 t 秒到大门口.每一秒,他都可以向上下左右四个方向移动一个点.一旦他移动了,他刚才所在的点就消失,(这意味着他不能回到他已经走过的点).他不能在一个…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 88774    Accepted Submission(s): 24159 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 55541    Accepted Submission(s): 14983 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…

题意  一仅仅狗要逃离迷宫  能够往上下左右4个方向走  每走一步耗时1s  每一个格子仅仅能走一次且迷宫的门仅仅在t时刻打开一次  问狗是否有可能逃离这个迷宫 直接DFS  直道找到满足条件的路径  或者走全然部可能路径都不满足 注意剪枝  当前位置为(r,c)  终点为(ex,ey) 剩下的时间为lt  当前点到终点的直接距离为  d=(ex-r)+(ey-c)   若多走的时间rt=lt-d<0 或为奇数时  肯定是不可能的  能够自己在纸上画一下 每一个点仅仅能走一次的图  走弯路的话多…

传送门:Tempter of the Bone 大意是给一个矩阵,叫你是否可以在给定的可走路径上不重复地走,在最后一秒走到终点. 我用了两个剪枝,且称其为简直001和剪枝002,事实证明001不要都可以,002不要也能过--||.就当练习一下剪枝. 特别是002很有用: if( d % 2 != (Time-t) % 2 ) return false ; (d=~x+~y) #include<cstdio> #include<cstdlib> #include<iostrea…

描述 The doggie found a bone in an ancient maze, which fascinated him a lot. However, when he picked it up, the maze began to shake, and the doggie could feel the ground sinking. He realized that the bone was a trap, and he tried desperately to get out…

The doggie found a bone in an ancient maze, which fascinated him a lot. However, when he picked it up, the maze began to shake, and the doggie could feel the ground sinking. He realized that the bone was a trap, and he tried desperately to get out of…