Problem Description After months of hard working, Iserlohn finally wins awesome amount of scholarship. As a great zealot of sneakers, he decides to spend all his money on them in a sneaker store. There are several brands of sneakers that Iserlohn wan…

分组背包要求每一组里面只能选一个,这个题目要求每一组里面至少选一个物品. dp[i, j] 表示前 i 组里面在每组至少放进一个物品的情况下,当花费 j 的时候,所得到的的最大价值.这个状态可以由三个状态转移过来: dp[i-1, v-a[i,j].b] 表示第 i 组没有放过,将要放进第 i 组里面的第 j 个物品 dp[i, v-a[i,j].b] 表示第 i 组已经放过了,将要放进第 i 组里面的第 j 个物品 dp[i, j] 表示第 i 中已经放过了,不放第 i 组里面的第 j 个物品…

这题的动态转移方程真是妙啊,完美的解决了每一种衣服必须买一件的情况. if(a[x][i-c[x][j].x]!=-1) a[x][i]=max(a[x][i],a[x][i-c[x][j].x]+c[x][j].y); if(a[x-1][i-c[x][j].x]!=-1) a[x][i]=max(a[x][i],a[x-1][i-c[x][j].x]+c[x][j].y); 第一个if里的条件是如果该种物品已经被选,那么,就按照一般的背包问题讨论 第二个if里的条件是如果上一种的物品被选,那…

这个题很怪,一开始没仔细读题,写了个简单的分组背包交上去,果不其然WA. 题目分析: 分组背包问题是这样描述的:有K组物品,每组 i 个,费用分别为Ci ,价值为Vi,每组物品是互斥的,只能取一个或者不取(最多取一个),求在一定背包容量V的情况下,能够获得的最大价值. 而这个题是,他每个牌子的鞋最少会买一双,但不会买一个牌子同款的两次. 也就是说如果将每个牌子分成一组,那么在每组里面要至少取一双,所以这更像是在每组里面进行01背包. 普通的分组背包的三层循环是: ; k<K; k++) ; v-…

题目大意 有 n 个物品,分成了 k 组,每个物品有体积和价值,把 n 个物品放到容量为 V 的背包中,保证每组至少放一件,求能获得的最大价值,如果不能实现,输出"Impossible". 样例 样例输入 1 5 10000 3 1 4 6 2 5 7 3 4 99 1 55 77 2 44 66 样例输出 1 255 样例 1 说明 选取物品 1,2,3,4 能够获得最大价值. 分析 标准的分组背包是每组最多选一个,这次变成了每组至少选一个. 最开始想到了一半,既然是每组至少选一个,…

I love sneakers! Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 4602    Accepted Submission(s): 1893 Problem Description After months of hard working, Iserlohn finally wins awesome amount of s…

I love sneakers! Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4765    Accepted Submission(s): 1950 Problem Description After months of hard working, Iserlohn finally wins awesome amount of sc…

I love sneakers! Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description After months of hard working, Iserlohn finally wins awesome amount of scholarship. As a great zealot of sneakers, he decides to s…

I love sneakers! Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2884    Accepted Submission(s): 1180 Problem Description After months of hard working, Iserlohn finally wins awesome amount of s…

Problem Description After months of hard working, Iserlohn finally wins awesome amount of scholarship. As a great zealot of sneakers, he decides to spend all his money on them in a sneaker store. There are several brands of sneakers that Iserlohn wan…