洛谷P2871 [USACO07DEC]手链Charm Bracelet

题目描述

Bessie has gone to the mall's jewelry store and spies a charm bracelet. Of course, she'd like to fill it with the best charms possible from the N (1 ≤ N ≤ 3,402) available charms. Each charm i in the supplied list has a weight Wi (1 ≤ Wi ≤ 400), a 'desirability' factor Di (1 ≤ Di ≤ 100), and can be used at most once. Bessie can only support a charm bracelet whose weight is no more than M (1 ≤ M ≤ 12,880).

Given that weight limit as a constraint and a list of the charms with their weights and desirability rating, deduce the maximum possible sum of ratings.

Bessie去购物中心的珠宝店偷了一只手链。当然，她想把最好的魅力可能从N（1≤N≤3402）可用的魅力。每个魅力我提供的名单中有一个权重Wi（1≤无线≤400），一个“愿望”的因素狄（1≤迪≤100），并且可以用在最一次。贝茜只能支持一个手链的重量不超过M（1≤M≤12880）。

以重量限制为约束，并以其权重和可取性等级列出魅力，推导出最大可能的和之和。

有N件物品和一个容量为V的背包。第我件物品的重量是C [我]，[我]价值是W。求解将哪些物品装入背包可使这些物品的重量总和不超过背包容量，且价值总和最大。

输入输出格式

输入格式：

• Line 1: Two space-separated integers: N and M

• Lines 2..N+1: Line i+1 describes charm i with two space-separated integers: Wi and Di

第一行：物品个数N和背包大小M

第二行至第N+1行：第i个物品的重量C[i]和价值W[i]

输出格式：

• Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints

输出一行最大价值。

输入输出样例

输入样例#1： 

4 61 42 63 122 7

输出样例#1： 

23

经典01背包问题。

附代码：

#include<iostream>#include<algorithm>#include<cstdio>#define MAXN 4010#define MAXM 20010using namespace std;int n,m,c[MAXN],w[MAXN],f[MAXM];inline int read(){int date=0,w=1;char c=0;while(c<'0'||c>'9'){if(c=='-')w=-1;c=getchar();}while(c>='0'&&c<='9'){date=date*10+c-'0';c=getchar();}return date*w;}int main(){n=read();m=read();for(int i=1;i<=n;i++){c[i]=read();w[i]=read();}for(int i=1;i<=n;i++)for(int j=m;j>=c[i];j--)f[j]=max(f[j],f[j-c[i]]+w[i]);printf("%d\n",f[m]);return 0;}