Description "Fat and docile, big and dumb, they look so stupid, they aren't much fun..." - Cows with Guns by Dana Lyons The cows want to prove to the public that they are both smart and fun. In order to do this, Bessie has organized an exhibitio…

POJ-2184 [题意]: 有n头牛,每头牛有自己的聪明值和幽默值,选出几头牛使得选出牛的聪明值总和大于0.幽默值总和大于0,求聪明值和幽默值总和相加最大为多少. [分析]:变种的01背包,可以把幽默度看成体积,智商看成价值,那么就转换成求体积和价值都为正值的最大值的01背包了. 以 TS 作为体积,TF作为价值,在保证体积.价值非负的情况下,求解 sum,取其所有情况的最大值. 难点: 1)体积出现负数,将区间改变 [-100000, 100000] ---> [0, 200000]. (注…

题目链接: https://vjudge.net/problem/POJ-2184 题目大意: 给出num(num<=100)头奶牛的S和F值(-1000<=S,F<=1000),要求在这几头奶牛中选出若干头,使得在其总S值TS和总F值TF均不为负的前提下,求最大的TS+TF值 思路: 可以把S当体积,F当价值做01背包.但是注意是S可为负,所以整体加100000,然后要注意DP顺序,S为负是要顺序,为正时逆序. 还有就是注意DP时的范围,凡是可能影响的都要包括. //#include&…

Cow Exhibition Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10200   Accepted: 3977 Description "Fat and docile, big and dumb, they look so stupid, they aren't much fun..." - Cows with Guns by Dana Lyons The cows want to prove to…

题目大意:已知c[i]...c[n]及f[i]...f[n],现要选出一些i,使得当sum{c[i]}和sum{f[i]}均非负时,sum(c[i]+f[i])的最大值. 以sum(c[i])(c[i]>=0)作为背包容量totV,i当作物体,c[i]当作物体体积,f[i]当作物体重量,01背包后,求max{j+DP[j]} (非负)即可. 注意: 这里物体体积存在负数,所以循环j时起始条件不能为j=0!而应当在for下面加if,判断子问题在minJ~maxJ范围之内. 初值不是DP[最左端点]…

\(\mathrm{Cow Poetry}\) 问题描述 LG5196 题解 因为每句诗的长度一定是\(k\),所以自然而然想到背包. 设\(opt[i][j]\)代表到第\(i\)位时,结尾为\(j\)的方案数. 背包,注意\(\mathrm{DP}\)顺序为先枚举\(i\),后枚举单词.(Debug了一小时就因为这个) 然后乘法原理统计答案即可. \(\mathrm{Code}\) #include<bits/stdc++.h> using namespace std; void read…

Balance Time Limit: 1000 MS Memory Limit: 30000 KB 64-bit integer IO format: %I64d , %I64u Java class name: Main [Submit] [Status] [Discuss] Description Gigel has a strange "balance" and he wants to poise it. Actually, the device is different fr…

0/1背包 给出n个物品,每个物品有Vi的价值和Wi的费用,我们总共有m块钱,求最多能得到多少价值的物品. N<=10^3,m<=10^3 记录方案数?记录输出方案? 输出方案: 对每个dp[i][j]记录是由哪个状态转移过来的,然后从最后一直往前找,输出: 最优策略方案数:再定义一个数组f[i][j]=dp[i-1][j]>dp[i-1][j-w[i]]+v[i]?f[i-1][j]:f[i-1][j-w[i]]; if(dp[i-1][j]==dp[i-1][j-w[i]]+v[i]…

Description One of the more popular activities in San Antonio is to enjoy margaritas in the park along the river know as the River Walk. Margaritas may be purchased at many establishments along the River Walk from fancy hotels to Joe's Taco and Marga…

/** * 判断是否为数字,包含负数情况 * @param str * @return */ private boolean isNumeric(String str){ Boolean flag = false; String tmp; if(StringUtils.isNotBlank(str)){ if(str.startsWith("-")){ tmp = str.substring(1); }else{ tmp = str; } flag = tmp.matches(&quo…