BZOJ 3963 HDU3842 [WF2011]MachineWorks cdq分治 斜率优化 dp

http://acm.hdu.edu.cn/showproblem.php?pid=3842

写的check函数里写的<但是应该是<=，调了一下午，我是个zz。

就是普通的斜率优化因为有两层需要排序的所以一层sort一层cdq分治

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
#define LL long long
#define pa pair< long long ,long long >
const int maxn=100100;
int n;
LL D,C;
struct nod{
    LL d,p,r,g,h;
}a[maxn];
LL f[maxn];
pa e[maxn],sta[maxn];
bool mcmp(nod aa,nod bb){
    return aa.d<bb.d;
}
bool Chk(pa aa,pa bb,pa cc){
    return ((double)((double)(aa.second-bb.second)*(double)(cc.first-bb.first)-
        (double)(bb.second-cc.second)*(double)(bb.first-aa.first)))>=0;
}
void mcdq(int l,int r){
    if(l==r)return;
    int mid=(l+r)/2;
    mcdq(l,mid);
    int cnt=0,tail=0;
    for(int i=l;i<=mid;i++){
        if(f[i]>=a[i].p){e[++cnt]=make_pair(a[i].g,a[i].h+f[i]);}
    }
    sort(e+1,e+1+cnt);
    for(int i=1;i<=cnt;i++){
        while(tail>1&&Chk(sta[tail-1],sta[tail],e[i]))tail--;
        sta[++tail]=e[i];
    }int j=1;//cout<<tail<<endl;
    for(int i=mid+1;i<=r;i++){
        while(j<tail&&sta[j].second+sta[j].first*a[i].d<sta[j+1].second+sta[j+1].first*a[i].d)j++;
        f[i]=max(f[i],sta[j].second+sta[j].first*a[i].d);
    }
    mcdq(mid+1,r);
}
int main(){
    int z=0;
    while(~scanf("%d%lld%lld",&n,&C,&D)){
        if(n==0&&C==0&&D==0)break;
        f[0]=C;
        for(int i=1;i<=n;i++){
            scanf("%lld%lld%lld%lld",&a[i].d,&a[i].p,&a[i].r,&a[i].g);
            a[i].h=a[i].r-a[i].p-(a[i].d+1)*a[i].g;
        }sort(a+1,a+1+n,mcmp);++n;
        a[n].d=D+1;a[n].g=a[n].p=0; a[n].h=0;
        for(int i=1;i<=n;i++)f[i]=f[i-1];
        mcdq(0,n);
        printf("Case %d: %lld
",++z,f[n]);
    }
    return 0;
}