Battle Ships is a new game which is similar to Star Craft. In this game, the enemy builds a defense tower, which has L longevity. The player has a military factory, which can produce N kinds of battle ships. The factory takes tiseconds to produce the…

Battle Ships is a new game which is similar to Star Craft. In this game, the enemy builds a defense tower, which has L longevity. The player has a military factory, which can produce N kinds of battle ships. The factory takes ti seconds to produce th…

dp[x][y]表示以x为根的子树要变成有y个点..最少需要减去的边树... 最终ans=max(dp[i][P]+t)  < i=(1,n) , t = i是否为整棵树的根 > 更新的时候分为两种情况..一种是要从其这个孩子转移过来...枚举做01背包..更新出每个状态的最小值..或者说直接砍掉这个孩子..那么只需将所有的状态多加个砍边... 这里的枚举做01背包..意思是由于叶子节点要放多少进去不确定..叶子节点要放的大小以及本节点的空间都在枚举更新...这种概念就是泛化背包..本质上是0…

dp[x][y]代表以x为根的子树..连接了y个终端用户(叶子)..所能获得的最大收益... dp[x][ ]可以看成当根为x时..有个背包空间为0~m...每个空间上记录了到到达这个空间的最大收益.. 典型的泛化背包问题... Program: #include<iostream> #include<stdio.h> #include<string.h> #include<set> #include<ctime> #include<alg…

link:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3623 看起来像完全背包,但是物品价值是变化的,所以很多人搞的很复杂. 晚上的代码要么很复杂,有一个代码虽然很简洁在zoj可以过,但是是错误的.求教lyl神犇,果然思想很深刻,抓住乐问题的本质,想法比网上搜到的所有博客里面的做法都简洁. 事实上,就是简单的DP,抓住一个技巧:让时间倒流,也就是说,把时间反过来考虑,先在将来把船造好,然后在过去用船攻击,哈哈,太巧秒…

刚看题...觉得这不是棵树...可能有回路...仔细一想..这还真是棵树(森林)...这是由于每个城堡所需要提前击破的城堡至多一个..对于一个城堡.其所需提前击破的城堡作为其父亲构图.... dp[k][i]代表以k为跟的子树击破i个城堡所能获得的最大收益...泛化背包问题... Program: #include<iostream> #include<stack> #include<queue> #include<stdio.h> #include<…

描述 且说上一周的故事里,小Hi和小Ho费劲心思终于拿到了茫茫多的奖券!而现在,终于到了小Ho领取奖励的时刻了! 小Ho现在手上有M张奖券,而奖品区有N件奖品,分别标号为1到N,其中第i件奖品需要need(i)张奖券进行兑换,同时也只能兑换一次,为了使得辛苦得到的奖券不白白浪费,小Ho给每件奖品都评了分,其中第i件奖品的评分值为value(i),表示他对这件奖品的喜好值.现在他想知道,凭借他手上的这些奖券,可以换到哪些奖品,使得这些奖品的喜好值之和能够最大. 提示一:合理抽象问题.定义状态是动态…

B - Battle Ships Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%lld & %llu Submit Status Practice ZOJ 3623 Appoint description:   Description Battle Ships is a new game which is similar to Star Craft. In this game, the enemy builds a…

传送门Battle Ships Time Limit: 2 Seconds      Memory Limit: 65536 KB Battle Ships is a new game which is similar to Star Craft. In this game, the enemy builds a defense tower, which has L longevity. The player has a military factory, which can produce N…

Battle Ships Time Limit: 2 Seconds      Memory Limit: 65536 KB Battle Ships is a new game which is similar to Star Craft. In this game, the enemy builds a defense tower, which has L longevity. The player has a military factory, which can produce N ki…