BZOJ3963: [WF2011]MachineWorks

题目链接：http://www.lydsy.com/JudgeOnline/problem.php?id=3963

CDQ分治加凸包。具体看这篇题解：http://www.acmerblog.com/hdu-3842-machine-works-6844.html

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<algorithm>
 #include<cmath>
 #define inf 1<<30
 #define maxn 100005
 #define ll long long
 using namespace std;
 int n,c,d,cases;
 long long f[maxn];
 int read(){
     int x=,f=; char ch;
     for(ch=getchar();ch<''||ch>'';ch=getchar()) if(ch=='-') f=-;
     for(;ch>=''&&ch<='';ch=getchar()) x=x*+ch-'';
     return x*f;
 }
 struct fuck{int d,p,r,g; void init(){d=read();p=read();r=read();g=read();}}m[maxn];
 typedef pair<int,long long> pa;
 pa a[maxn],b[maxn];
 long long h(int x){return f[x]-(ll)m[x].p+(ll)m[x].r-(ll)m[x].g*(ll)(m[x].d+);}
 bool cmp(fuck x,fuck y){return x.d<y.d;}
 bool check(pa a,pa b,pa c){
     ll xa=b.first-a.first; ll xb=c.first-a.first;
     ll ya=b.second-a.second; ll yb=c.second-a.second;
     double tmp=(double)xa*yb-(double)ya*xb;
     return tmp<;
 }
 void solve(int l,int r){
     if(l==r) return;
     int mid=(l+r)>>;
     solve(l,mid);
     int na=,nc=;
     for(int i=l;i<=mid;i++){
         if(f[i]>=m[i].p) a[++na]=pa(m[i].g,h(i));
     }
     sort(a+,a+na+);
     for(int i=;i<=na;i++){
         while(nc>&&!check(b[nc-],b[nc],a[i])) nc--;
         b[++nc]=a[i];
     }
     int j=;
     for(int i=mid+;i<=r;i++){
         ll a1,a2,b1,b2,x;
         x=m[i].d;
         while(j<nc){
             a1=b[j].first; a2=b[j+].first;
             b1=b[j].second; b2=b[j+].second;
             if(a1*x+b1>=a2*x+b2) break;
             j++;
         }
         f[i]=max(f[i],(ll)b[j].first*x+b[j].second);
     }
     solve(mid+,r);
 }
 int main(){
     for(n=read(),c=read(),d=read();n&&c&&d;n=read(),c=read(),d=read()){
         for(int i=;i<=n;i++) m[i].init();
         sort(m+,m+n+,cmp);
         m[++n].d=d+; m[n].p=m[n].r=m[n].g=;
         for(int i=;i<=n;i++) f[i]=c;
         solve(,n);
         printf("Case %d: %lld\n",++cases,f[n]);
     }
     return ;
 }