看题传送门:http://poj.org/problem?id=1018 题目大意: 某公司要建立一套通信系统,该通信系统需要n种设备,而每种设备分别可以有m个厂家提供生产,而每个厂家生产的同种设备都会存在两个方面的差别:带宽bandwidths 和 价格prices. 现在每种设备都各需要1个,考虑到性价比问题,要求所挑选出来的n件设备,要使得B/P最大. 其中B为这n件设备的带宽的最小值,P为这n件设备的总价. 思路: 贪心+枚举 要使得B/P最大,则B应该尽量大,而P尽量小. 可以按照价格…

Communication System Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 21631   Accepted: 7689 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices.…

Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, we are free to choose from several manufacturers. Same devices from two manufacturers d…

Communication System Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 22380   Accepted: 7953 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices.…

Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, we are free to choose from several manufacturers. Same devices from two manufacturers d…

点击打开链接 Communication System Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 21007   Accepted: 7449 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several d…

We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, we are free to choose from several manufacturers. Same devices from two manufacturers differ in the…

http://poj.org/problem?id=1018 题意: 某公司要建立一套通信系统,该通信系统需要n种设备,而每种设备分别可以有m1.m2.m3.....mn个厂家提供生产,而每个厂家生产的同种设备都会存在两个方面的差别:带宽bandwidths 和 价格prices. 现在每种设备都各需要1个,考虑到性价比问题,要求所挑选出来的n件设备,要使得B/P最大. 其中B为这n件设备的带宽的最小值,P为这n件设备的总价. 思路:DP解决. d[i][j]代表选择第i个设备时最小带宽j时的价…

题意:给你n个厂,每个厂有m个产品,产品有B(带宽),P(价格),现在要你求最大的 B/P 明显是枚举,当P大于一定值,B/P为零,可以用这个剪枝 #include <iostream> #include<cstring> #include<cstdio> using namespace std; #define N 110 #define INF 0xffffff int devb[N][N],devp[N][N]; int b[N*100],tb; int main…

本题一看似乎是递归回溯剪枝的方法.我一提交,结果超时. 然后又好像是使用DP,还可能我剪枝不够. 想了非常久,无奈忍不住偷看了下提示.发现方法真多.有贪心,DP,有高级剪枝的.还有三分法的.八仙过海各显神通啊. 坏习惯了,没思考够深入就偷看提示了. 幸好及时回头,还不须要看别人的代码了.自己做出来之后,有空看看多种解法的代码也好. 然后我想出自己的思路了,使用贪心,剪枝,DP综合优化下,呵呵.最后程序有点复杂.优化到了16ms,运气好点,或者vector换成原始数组的话,应该能够0MS了. 整体…

                                                                          通讯系统 We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, we are free to choos…

Communication System Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 29218   Accepted: 10408 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices…

Communication System Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 25006 Accepted: 8925 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For…

POJ 3190 Stall Reservations贪心 Description Oh those picky N (1 <= N <= 50,000) cows! They are so picky that each one will only be milked over some precise time interval A..B (1 <= A <= B <= 1,000,000), which includes both times A and B. Obvi…

We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, we are free to choose from several manufacturers. Same devices from two manufacturers differ in the…

Communication System Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 25653   Accepted: 9147 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices.…

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…

个人心得:百度推荐的简单DP题,自己做了下发现真得水,看了题解发现他们的思维真得比我好太多太多, 这是一段漫长的锻炼路呀. 关于这道题,我最开始用DP的思路,找子状态,发现自己根本就不会找DP状态数组建立,怎么找都是被后面的给打乱了, 看到了网上的DP[i][j],i表示前几个设备,宽带为j的最少花费,哇,真得厉害,突然发现动态规划并不需要做到问题很完美, 其实只要解决方案能够顺带把这个解决就好了. 他的这个转移方程就是,当i等于1时,输入的想,输入的x,y(x表示宽带长度,y表示价格)dp[i…

  Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 26738   Accepted: 9546 Description We have received an order from Pizoor Communications Inc. for a special communication system. The system consists of several devices. For each device, w…

POJ 1161 Walls(最短路+枚举) 题目背景 题目大意:题意是说有 n个小镇,他们两两之间可能存在一些墙(不是每两个都有),把整个二维平面分成多个区域,当然这些区域都是一些封闭的多边形(除了最外面的一个),现在,如果某几个小镇上的人想要聚会,为选择哪个区域为聚会地点,可以使他们所有人总共需要穿过的墙数最小,题目上有说明,不在某个点上聚会(聚会点在某个多边形内部),行进过程中不穿过图中的点(也就是除出发点外的其他小镇). 输入第1行代表m(2<=M<=200)个区域 第2行代表n(3&…

题目链接:http://poj.org/problem?id=1018 题目大意:有n种通讯设备,每种有mi个制造商,bi.pi分别是带宽和价格.在每种设备中选一个制造商让最小带宽B与总价格P的比值B/P最大. 解法是枚举最小带宽B,每种设备在带宽大于B的制造商中找价格最小的,最后取比值最大的. 详见代码: #include<cstdio> #include<cmath> #include<cstring> #include<algorithm> using…

题意: 给出n个工厂的产品参数带宽b和价格p,在这n个工厂里分别选1件产品共n件,使B/P最小,其中B表示n件产品中最小的b值,P表示n件产品p值的和. 输入 iCase n 表示iCase个样例n个工厂 m1 p1 b1 p2 b2..pm1 bm1 //第一个工厂有m1个同种类不同参数的产品,每一个产品的参数分别是p1 b1 p2 b2 m2 p1 b1 p2 b2..pm2 bm2 ... mn p1 b1 p2 b2..pmn bmn 思路: 排序,先把b从小到大排序,然后把p从小到大排…

Smallest Difference Description Given a number of distinct decimal digits, you can form one integer by choosing a non-empty subset of these digits and writing them in some order. The remaining digits can be written down in some order to form a second…

Description Bessie noted that although humans have many universities they can attend, cows have none. To remedy this problem, she and her fellow cows formed a new university called The University of Wisconsin-Farmside,"Moo U" for short. Not wish…

poj1018:http://poj.org/problem?id=1018 题意:某公司要建立一套通信系统,该通信系统需要n种设备,而每种设备分别可以有m1.m2.m3.....mn个厂家提供生产,而每个厂家生产的同种设备都会存在两个方面的差别:带宽bandwidths 和 价格prices.现在每种设备都各需要1个,考虑到性价比问题,要求所挑选出来的n件设备,要使得B/P最大.其中B为这n件设备的带宽的最小值,P为这n件设备的总价.题解:方法一:暴力枚举.枚举每个bandwidth,然后从剩…

POJ 1328 Radar Installation https://vjudge.net/problem/POJ-1328 题目: Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point locating in the sea side. And any radar installation…

Stall Reservations Oh those picky N (1 <= N <= 50,000) cows! They are so picky that each one will only be milked over some precise time interval A..B (1 <= A <= B <= 1,000,000), which includes both times A and B. Obviously, FJ must create a…

http://poj.org/problem?id=1018 (题目链接) 题意 要买n个产品,每个产品有m种价格和宽度(我也不知道翻译过来到底是什么?),设n个产品的宽度的最小值为B,n个产品的价格和为P,要求B/P最大. Solution dp.题目没说B的取值范围,坑死了. f[i][j]表示前i个产品,当B为j时的最小价格. 转移很好转,具体见代码. 代码 // poj1018 #include<algorithm> #include<iostream> #include&…

Cleaning Shifts 题目连接: http://poj.org/problem?id=2376 Description Farmer John is assigning some of his N (1 <= N <= 25,000) cows to do some cleaning chores around the barn. He always wants to have one cow working on cleaning things up and has divided…

题目:http://poj.org/problem?id=3273 题意:把n个数分成m份,使每份的和尽量小,输出最大的那一个的和. 思路:二分枚举最大的和,时间复杂度为O(nlog(sum-max)); 一道很好的题. #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <algorithm> using namespace s…