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…

Vjudge传送门 $Sol$ 首先发现这是一个多重背包,所以可以用多重背包的一般解法(直接拆分法,二进制拆分法...) 但事实是会TLE,只能另寻出路 本题仅关注“可行性”(面值能否拼成)而不是“最优性”,这是一个特殊之处. 从这里找优化 在“最优性”的问题中,$f[j]$从$f[j]$或$f[j-a[i]]$中转移而来:而在这样的“可行性”问题中,其实只要$f[j]$可行,我们就可以不用考虑$f[j-a[i]$了,也可以反过来说. 于是我们可以考虑一种贪心策略,设$used[j]$表示$f[…

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…

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…

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…

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…

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…

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…

意甲冠军:你有N种硬币,每个价格值A[i],每个号码C[i],要求. 在不超过M如果是,我们用这些硬币,有多少种付款的情况下,.那是,:1,2,3,4,5,....,M这么多的情况下,,你可以用你的硬币不找零,种情况. 比如: 你有一种硬币,价值2.个数2,那么 你是不能付款 3元的..你仅仅能付款2,或者4元.. OK,题意差点儿相同就是这样啦. 那么这里有两种方式! 分析: 那么这里我们能够用多重背包来解决,我们把价值和重量看成一样的w[i] = A[i]:用M作为背包. 那么dp 过后.我…