bzoj4247: 挂饰（01背包）

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
struct node
{
int gou,val;
}edge[2500];
int cmp(node a,node b)
{
return a.gou>b.gou;
}
int n;
int ans;
int f[2500][2500];
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
scanf("%d %d",&edge[i].gou,&edge[i].val);
}
sort(edge+1,edge+1+n,cmp);
memset(f,-0x3f,sizeof(f));//别清大了
f[0][1]=0;
for(int i=1;i<=n;i++)
{
for(int j=0;j<=n;j++)
{
f[i][j]=max(f[i-1][j-edge[i].gou+1>1?j-edge[i].gou+1:1]+edge[i].val,f[i-1][j]);
}
}
for(int i=0;i<=n;i++)
{
ans=max(ans,f
[i]);
}
printf("%d",ans);
}