[bzoj1855][Scoi2010]股票交易_动态规划_单调队列

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define N 2010
using namespace std;
int t,maxp,w;
int f[N][N];
int q[N];
struct node
{
    int ap,bp,as,bs;
}a[N];
int main()
{
    scanf("%d%d%d",&t,&maxp,&w);
    for(int i=1;i<=t;i++)
    {
        scanf("%d%d%d%d",&a[i].ap,&a[i].bp,&a[i].as,&a[i].bs);
    }
    memset(f,-0x3f,sizeof(f));
    for(int i=1;i<=t;i++)
    {
        for(int j=0;j<=a[i].as;j++) f[i][j]=-a[i].ap*j;
        for(int j=0;j<=maxp;j++) f[i][j]=max(f[i][j],f[i-1][j]);
        if(i-w-1>=0)
        {
            int head=0,tail=0;
            for(int j=0;j<=maxp;j++)
            {
                while(head<tail&&q[head]<j-a[i].as)head++;
                while(head<tail&&f[i-w-1][j]+j*a[i].ap>=f[i-w-1][q[tail-1]]+q[tail-1]*a[i].ap)tail--;
                q[tail++]=j;
                if(head<tail)f[i][j]=max(f[i][j],f[i-w-1][q[head]]-(j-q[head])*a[i].ap);
            }
            head=0,tail=0;
            for(int j=maxp;j>=0;j--)
            {
                while(head<tail&&q[head]>j+a[i].bs)head++;
                while(head<tail&&f[i-w-1][j]+j*a[i].bp>=f[i-w-1][q[tail-1]]+q[tail-1]*a[i].bp)tail--;
                q[tail++]=j;
                if(head<tail)f[i][j]=max(f[i][j],f[i-w-1][q[head]]+(q[head]-j)*a[i].bp);
            }
        }
    }
    int ans=0;
    for(int i=0;i<=maxp;i++)
    {
        ans=max(ans,f[t][i]);
    }
    printf("%d\n",ans);
}