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.
Input
* 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
Output
* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints
Sample Input
4 6 1 4 2 6 3 12 2 7
Sample Output
23
我的代码:
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
//int dp[5005];
int w[5005],d[5005];
int max(int a,int b)
{
if(a > b)
return a;
else
return b;
}
int main()
{
int n,m;
while(scanf("%d %d",&n,&m)!=EOF)
{
int dp[20000]={0};
for(int i=0;i<n;i++)
{
scanf("%d %d",&w[i],&d[i]);
}
// memset(dp,0,sizeof(dp));
for(int i=0;i<n;i++)
{
for(int j=m;j>=w[i];j--)
{
dp[j] = max(dp[j],dp[j-w[i]] + d[i]);
}
}
printf("%d\n",dp[m]);
}
return 0;
}
这是一个很裸的01背包。只有拿与不拿两种情况,找个最大的就可以了。