该题与POJ 1742的思路基本一致:http://www.cnblogs.com/sevenun/p/5442279.html(多重背包) 题意:给你n个电梯,第i个电梯高h[i],数量有c[i]个,但是每个电梯所在高度不能超过a[i]. 求问,怎么样的建造方案能够使电梯能够达到最大高度 思路:首先,必然要使电梯按a[i]进行排序,a[i]最小的电梯先建造.例如,电梯1,只能在高度20以下建造,而电梯2能在高度50以下建造,我当然先建造电梯1,否则如果先建造电梯2,就会导致我建造的高度早早超过…

POJ 2392 Space Elevator(贪心+多重背包) http://poj.org/problem?id=2392 题意: 题意:给定n种积木.每种积木都有一个高度h[i],一个数量num[i].另一个限制条件,这个积木所在的位置不能高于limit[i],问能叠起的最大高度? 分析: 本题是一道多重背包问题, 只是每一个物品的选择不只要受该种物品的数量num[i]限制, 且该物品还受到limit[i]的限制. 这里有一个贪心的结论: 我们每次背包选取物品时都应该优先放置当前limit…

Description The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K ( <= K <= ) different types of blocks with which to build the tower. Each block of type i has height h_i (…

Q: 额外添加了最大高度限制, 需要根据 alt 对数据进行预处理么? A: 是的, 需要根据 alt 对数组排序 Description The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K <= 400) different types of blocks with w…

Description The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K <= 400) different types of blocks with which to build the tower. Each block of type i has height h…

题目链接: http://poj.org/problem?id=2392 题意: 给你k类方块,每类方块ci个,每类方块的高度为hi,现在要报所有的方块叠在一起,每类方块的任何一个部分都不能出现在ai以上的高度,问这些方块能叠的最高高度. 题解: 首先按ai升序排序,尽量让高度限制低的先排掉,如果不这样做一些转移会失效掉: 比如:h1=3,a1=3;h2=4,a2=7 如果先搭1再搭2则合法,但反过来则变成无效的转移了. 处理好顺序之后跑一遍背包就可以了,因为最大高度为40000,比较小,所以用…

多重背包.本题不须要二分优化.相对简单点.由于反复数十分小,小于10. 而添加一个限制每种材料的高度做法.假设使用逆向填表,那么仅仅须要从这个高度往小递归填表就能够了. 还有就是注意要排序,以限制高度为标准从小到大排序.否则答案错误的. #include <stdio.h> #include <string.h> #include <algorithm> using std::sort; const int MAX_K = 401; const int MAX_H =…

显然塔的总高度不会超过最大的a[i],而a[i]之前的可以到达的高度 是由a值更小的块组成,所以按照a从小到大的顺序去转移. 然后就是多重背包判断存在性了,几乎和coin那题一样. 数据没coin丧病,倍增可过,单调队列也可,不过还是优化定义最好写. #include<cstdio> #include<iostream> #include<string> #include<cstring> #include<queue> #include<…

A - Space Elevator Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have…

Space Elevator   Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8569   Accepted: 4052 Description The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K…