Problem Description Whuacmers use coins.They have coins of value A1,A2,A3...An Silverland dollar. One day Hibix opened purse and found there were some coins. He decided to buy a very nice watch in a nearby shop. He wanted to pay the exact price(witho…

Coins Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 12330    Accepted Submission(s): 4922 Problem Description Whuacmers use coins.They have coins of value A1,A2,A3...An Silverland dollar. One…

题目链接:https://cn.vjudge.net/problem/HDU-2844 题意 给你一些不同价值和一定数量n的硬币. 求用这些硬币可以组合成价值在[1 , m]之间的有多少. 思路 多重背包问题,看了一眼数据范围,用二进制优化一下物品数量即可. 提交过程 AC 代码 #include <cstdio> #include <cstring> #include <algorithm> using namespace std; const int maxn=10…

题目意思:给出你n种硬币的面额和数量,询问它能够组合成1~m元中的几种情况. 这题如果直接按照完全背包来写的话,会因为每一种硬币的数目1 ≤ Ci ≤ 1000而超时,所以这里需要运用二进制优化来解决问题. 二进制优化和快速幂的思路是一样的. 例如:面值为1的硬币有20枚,如果完全背包的话就需要20次状态转移. 运用二进制优化后,就变成了 面值为1的硬币1枚.面值为2的硬币1枚.面值为4的硬币1枚.面值为8的硬币1枚,最后多出的5个,就直接作为面值为5的硬币一枚,加入新的数组中.之前的20次转移…

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…

Coins Time Limit: 3000MS   Memory Limit: 30000K Total Submissions: 34814   Accepted: 11828 Description People in Silverland use coins.They have coins of value A1,A2,A3...An Silverland dollar.One day Tony opened his money-box and found there were some…

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…

Description People in Silverland use coins.They have coins of value A1,A2,A3...An Silverland dollar.One day Tony opened his money-box and found there were some coins.He decided to buy a very nice watch in a nearby shop. He wanted to pay the exact pri…

这道题是典型的多重背包的题目,也是最基础的多重背包的题目 题目大意:给定n和m, 其中n为有多少中钱币, m为背包的容量,让你求出在1 - m 之间有多少种价钱的组合,由于这道题价值和重量相等,所以就是dp[i] = i, 其中dp[i]表示当前背包容量为i 的时候背包能装的价值. 题目思路: 模板 二进制优化 话说那个二进制真的很奇妙,只需要2的1次方 到 2的k-1次方, 到最后在加上一项当前项的个数 - 2 的k次方 + 1,也就是这些系数分别为1; 2; 22 .....2k-1;Mi…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2844 题意:一位同学想要买手表,他有n种硬币,每种硬币已知有num[i]个.已知手表的价钱最多m元,问她用这些钱能够凑出多少种价格来买手表. 分析:二进制优化的多重背包,假设每种硬币为容量为val[i]且价值也为val[i]的物品,最后有dp[i]==i则能组成价格为i.因为容量为i能达到的最大价值也是i,刚好符合01背包的含义. #include <cstdio> #include <cs…