bzoj1835[ZJOI2010]base基站选址

#include<cstdio>
#include<cstring>
#include<cctype>
#include<algorithm>
using namespace std;
template<typename T>inline void read(T &x){
    char ch;while(ch=getchar(),!isdigit(ch));
    x=ch-‘0‘;
    while(ch=getchar(),isdigit(ch))x=x*10+ch-‘0‘;
}

const int maxn=20005,maxk=105;
int f[maxk][maxn];
int d[maxn],c[maxn],s[maxn],w[maxn];
int l[maxn],r[maxn],seq[maxn];
int n,k;
struct node{
    int sum;node *lch,*rch;
}t[maxn*50];int cnt=0;//11mb
node *root[maxn];
void Insert(node *rt1,node* &rt2,const int &k,const int &w,int l,int r){
    ++cnt;rt2=t+cnt;
    if(l==r){
        rt2->sum=rt1->sum+w;
        return;
    }
    int mid=(l+r)>>1;
    if(k<=mid){
        rt2->rch=rt1->rch;
        Insert(rt1->lch,rt2->lch,k,w,l,mid);
    }else{
        rt2->lch=rt1->lch;
        Insert(rt1->rch,rt2->rch,k,w,mid+1,r);
    }
    rt2->sum=rt2->lch->sum+rt2->rch->sum;
}
void build_all(){
    root[0]=t+0;root[0]->lch=root[0]->rch=t+0;
    int cur=0;
    for(int i=1;i<=n;++i){
        if(r[seq[i]]>cur){
            while(cur!=r[seq[i]]){
                root[cur+1]=root[cur];
                ++cur;
            }
        }
        Insert(root[cur],root[cur],l[seq[i]],w[seq[i]],1,n);
    }
    for(int i=cur+1;i<=n;++i)root[i]=root[i-1]; 
}
int query(node *rt1,node *rt2,int k,int l,int r){//有多少数字比k大 
   // printf("q%d %d",l,r);
    if(l>k){
        return rt2->sum-rt1->sum;
    }
    int mid=(l+r)>>1;
    if(k<mid)return query(rt1->lch,rt2->lch,k,l,mid)+query(rt1->rch,rt2->rch,k,mid+1,r);
    else return query(rt1->rch,rt2->rch,k,mid+1,r);
}
int qsum(int l,int r){//l,r各自有一个基站 
    return query(root[l],root[r-1],l,1,n);
} 
bool cmp(const int &a,const int &b){
    return r[a]<r[b];
}
bool cmp2(const int &a,const int &b){
    return l[a]<l[b];
}
int s1[maxn],s2[maxn]; 
int st[maxn];int top=0,mk=0;//st:单调栈 
int L[maxn],R[maxn];//每个决策对应的左右区间 
inline bool inside(int i,int x){
    return L[x]<=i&&i<=R[x];
}
int binary(int l,int r,int x,int a,int b){//在f[l]..f[r]找出第一个决策b比决策a优的位置
    while(l<=r){
        int mid=(l+r)>>1;
        if(f[x-1][a]+qsum(a,mid)<f[x-1][b]+qsum(b,mid))l=mid+1;
        else r=mid-1;
    } 
    return r+1;
}
void work(int x){//x-1 -> x
    //使用x个基站，那么至少已经建到了x 
    top=0;mk=0;
/*    st[++top]=x-1;mk=1;
    L[top]=x;R[top]=n;*/
    for(int i=x;i<=n;++i){
        while(top!=0&&(i-1)<L[top]&&((f[x-1][st[top]]+qsum(st[top],L[top]))>(f[x-1][i-1]+qsum(i-1,L[top])))){
            top--;
        }
        //binary
        if(top!=0){
            int tmp;
            if(i-1<L[top])tmp=binary(L[top],R[top],x,st[top],i-1);
            else tmp=binary(i,R[top],x,st[top],i-1);
            R[top]=tmp-1;
        }
        st[++top]=i-1;L[top]=R[top-1]+1;R[top]=n;
        while(!inside(i,mk))mk++;
        f[x][i]=c[i]+f[x-1][st[mk]]+qsum(st[mk],i);//printf("%d %d %d %d %d\n",mk,x-1,st[mk],x,i);
    } 
}
int main(){
   // freopen("base.in","r",stdin);
  //  freopen("base.out","w",stdout);
    memset(f,0x7f,sizeof(f));
    read(n);read(k);
    for(int i=2;i<=n;++i){
        read(d[i]);
    }
    for(int i=1;i<=n;++i){
        read(c[i]);
    }
    for(int i=1;i<=n;++i){
        read(s[i]);
        l[i]=lower_bound(d+1,d+n+1,d[i]-s[i])-d;r[i]=upper_bound(d+1,d+n+1,d[i]+s[i])-d-1;
    }
    for(int i=1;i<=n;++i)read(w[i]);
    for(int i=1;i<=n;++i)seq[i]=i;
    int sum=0;
    for(int i=1;i<=n;++i){
        sum+=w[i];
    }
    if(k==0){
        printf("%d\n",sum);
    }else{
        sort(seq+1,seq+n+1,cmp);
        build_all();
        for(int i=1;i<=n;++i){
            s1[r[i]]+=w[i];
        }
        for(int i=1;i<=n;++i){
            s1[i]+=s1[i-1];
        }sort(seq+1,seq+n+1,cmp2);
        for(int i=1;i<=n;++i){
            s2[l[i]]+=w[i];
        }
        for(int i=n;i>=1;--i){
            s2[i]+=s2[i+1];
        }
        int ans=sum;
        for(int i=1;i<=n;++i){
            f[1][i]=s1[i-1]+c[i];
            int tmp=f[1][i]+s2[i+1];
            if(tmp<ans)ans=tmp;
        }
        for(int j=2;j<=k&&j<=n;++j){
            work(j);
        } 
        for(int i=1;i<=n;++i){
            for(int j=2;j<=k&&j<=n;++j){
                if(f[j][i]+s2[i+1]<ans)ans=f[j][i]+s2[i+1];
            }
        }
        printf("%d\n",ans); 
    }//while(1);
   // fclose(stdin);fclose(stdout);
    return 0;
}