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 61 42 63 122 7

输出样例#1：

23 思路： 　　裸01背包； 来，上代码：

#include 
       
        #include 
        
         #include 
         
          using namespace std;int if_z,dp[15005],n,m,vi,ci;char Cget;inline void in(int &now){    now=0,if_z=1,Cget=getchar();    while(Cget>'9'||Cget<'0')    {        if(Cget=='-') if_z=-1;        Cget=getchar();    }    while(Cget>='0'&&Cget<='9')    {        now=now*10+Cget-'0';        Cget=getchar();    }    now*=if_z;}int main(){    in(n),in(m);    while(n--)    {        in(vi),in(ci);        for(int i=m;i>=vi;i--) dp[i]=max(dp[i],dp[i-vi]+ci);    }    cout<