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=;
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)))>=;
}
void mcdq(int l,int r){
if(l==r)return;
int mid=(l+r)/;
mcdq(l,mid);
int cnt=,tail=;
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+,e++cnt);
for(int i=;i<=cnt;i++){
while(tail>&&Chk(sta[tail-],sta[tail],e[i]))tail--;
sta[++tail]=e[i];
}int j=;//cout<<tail<<endl;
for(int i=mid+;i<=r;i++){
while(j<tail&&sta[j].second+sta[j].first*a[i].d<sta[j+].second+sta[j+].first*a[i].d)j++;
f[i]=max(f[i],sta[j].second+sta[j].first*a[i].d);
}
mcdq(mid+,r);
}
int main(){
int z=;
while(~scanf("%d%lld%lld",&n,&C,&D)){
if(n==&&C==&&D==)break;
f[]=C;
for(int i=;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+)*a[i].g;
}sort(a+,a++n,mcmp);++n;
a[n].d=D+;a[n].g=a[n].p=; a[n].h=;
for(int i=;i<=n;i++)f[i]=f[i-];
mcdq(,n);
printf("Case %d: %lld\n",++z,f[n]);
}
return ;
}