洛谷——P2871 [USACO07DEC]手链Charm Bracelet

https://www.luogu.org/problem/show?pid=2871

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.

有N件物品和一个容量为V的背包。第i件物品的重量是c[i]，价值是w[i]。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

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

输入输出样例

输入样例#1：

4 6
1 4
2 6
3 12
2 7

输出样例#1：

23

#include <algorithm>
#include <iostream>
#include <cstdio>

using namespace std;

int n,m,w[120053],val[120053];
int f[120053];

int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        scanf("%d%d",&w[i],&val[i]);
    for(int i=1;i<=n;i++)
        for(int V=m;V>=w[i];V--)
            f[V]=max(f[V],f[V-w[i]]+val[i]);
    printf("%d",f[m]);
    return 0;
}