POJ 3260 The Fewest Coins(多重背包+全然背包) http://poj.org/problem?id=3260 题意: John要去买价值为m的商品. 如今的货币系统有n种货币,相应面值为val[1],val[2]-val[n]. 然后他身上每种货币有num[i]个. John必须付给售货员>=m的金钱, 然后售货员会用最少的货币数量找钱给John. 问你John的交易过程中, 他给售货员的货币数目+售货员找钱给他的货币数目 的和最小值是多少? 分析: 本题与POJ 12…

题目代号:POJ 3260 题目链接:http://poj.org/problem?id=3260 The Fewest Coins Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 6715 Accepted: 2072 Description Farmer John has gone to town to buy some farm supplies. Being a very efficient man, he alway…

[题目链接] http://poj.org/problem?id=3260 [题目大意] 给出你拥有的货币种类和每种的数量,商店拥有的货币数量是无限的, 问你买一个价值为m的物品,最少的货币流通数量为多少 [题解] 我们可以计算出买不同价值的物品,在没有找钱情况下的最少用币数量, 记为dp[i],这个可以用多重背包来完成,对于商店来说,我们可以计算出, 对于不同额度的找零,最少用币数量,记为f[i], 我们发现,对于货币流通最少,就是求dp[i+m]+f[i]的最小值, 由鸽巢原理可得我们只要计…

Q: 既是多重背包, 还是找零问题, 怎么处理? A: 题意理解有误, 店主支付的硬币没有限制, 不占额度, 所以此题不比 1252 难多少 Description Farmer John has gone to town to buy some farm supplies. Being a very efficient man, he always pays for his goods in such a way that the smallest number of coins change…

// 转载自http://blog.163.com/benz_/blog/static/18684203020115721917109/算法不难看出,就是一个无限背包+多重背包.问题在于背包的范围.设John出了X元,则需要找零X-T元.证明X不超过T+v_max^2:假设超过了,则找零超过v_max^2,则找零的货币数定超过v_max,根据抽屉原理,必然有若干个货币组合起来是v_max的倍数,那么这些货币肯定可以在给钱的时候少给一些,从而推出这样的方案肯定不是最优方案.复杂度:O(n*(T+v…

题意:FJ身上有各种硬币,但是要买m元的东西,想用最少的硬币个数去买,且找回的硬币数量也是最少(老板会按照最少的量自动找钱),即掏出的硬币和收到的硬币个数最少. 思路:老板会自动找钱,且按最少的找,硬币数量也不限,那么可以用完全背包得出组成每个数目的硬币最少数量.而FJ带的钱是有限的,那么必须用多重背包,因为掏出的钱必须大于m,那么我们所要的是大于等于m钱的硬币个数,但是FJ带的钱可能很多,超过m的很多倍都可能,那么肯定要有个背包容量上限,网上说的根据抽屉原理是m+max*max,这里的max指…

The Fewest Coins POJ - 3260 完全背包+多重背包.基本思路是先通过背包分开求出"付出"指定数量钱和"找"指定数量钱时用的硬币数量最小值,然后枚举找的钱,那么付出的钱也随之确定,对于每个枚举出的找的钱可以得到一个答案,那么枚举所有可能的找的钱取答案的最大值即可. 这里有一个对于找钱上限的证明.如果不知道,也可以随便搞一个(比如以下用的10000,注意空间,试过5000可以过). 错误记录: 4.多重背包优化中,把除以2写成<<=2…

The Fewest Coins Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6299   Accepted: 1922 Description Farmer John has gone to town to buy some farm supplies. Being a very efficient man, he always pays for his goods in such a way that the sm…

The Fewest Coins DescriptionFarmer John has gone to town to buy some farm supplies. Being a very efficient man, he always pays for his goods in such a way that the smallest number of coins changes hands, i.e., the number of coins he uses to pay plus…

http://poj.org/problem?id=3260   Description Farmer John has gone to town to buy some farm supplies. Being a very efficient man, he always pays for his goods in such a way that the smallest number of coins changes hands, i.e., the number of coins he…