zcmimi's blog
avatar
zc
2019-12-21 19:47:00
  • 本文总阅读量
查看原题

点击跳转

先用set预处理出离每个点最近的点和第二近的点

n~1 每次往set里插入{a[i],i} 然后把前驱后继找出来比较一下 具体看代码

(听说有排序后双向链表的神仙做法)

接着用倍增处理出开2^i循环次的数据

然后就直接暴力

具体看代码,码风有点新奇

#include<bits/stdc++.h>
namespace ZDY{
    #pragma GCC optimize(3)
    #define il __inline__ __attribute__ ((always_inline))
    #define rg register
    #define ll long long
    #define ull unsigned long long
    #define db double
    #define sht short
    #define MB template <class T>il
    #define Fur(i,x,y) for(int i=x;i<=y;i++)
    #define Fdr(i,x,y) for(int i=x;i>=y;i--)
    #define fl(i,x) for(int i=head[x],to;to=e[i].to,i;i=e[i].nxt)
    #define clr(x,y) memset(x,y,sizeof(x))
    #define cpy(x,y) memcpy(x,y,sizeof(x))
    #define fin(s) freopen(s".in","r",stdin)
    #define fout(s) freopen(s".out","w",stdout)
    #define fcin ios::sync_with_stdio(false)
    #define l2(n) (int(log2(n)))
    #define inf 0x3f3f3f3f
    MB T ABS(T x){return x>0?x:-x;}
    MB T MAX(T x,T y){return x>y?x:y;}
    MB T MIN(T x,T y){return x<y?x:y;}
    MB T GCD(T x,T y){return y?GCD(y,x%y):x;}
    MB void SWAP(T &x,T &y){T t=x;x=y;y=t;}
}using namespace ZDY;using namespace std;
namespace IO{const char* ln="\n";const int str=1<<20;struct IN{char buf[str],*s,*t;bool _;IN():s(buf),t(buf),_(0){}il char gc(){return s==t&&((t=(s=buf)+fread(buf,1,str,stdin))==s)?EOF:(*s++);}IN&operator>>(char&ch){if(_)return *this;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF)_=1;else ch=c;return *this;}IN& operator>>(char* ch){if(_)return *this;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF)return _=1,*this;*ch=c;ch++;while((c=gc())!=EOF&&!isspace(c))*ch=c,ch++;if(c==EOF)_=1;return *this;}IN& operator>>(string& ch){if(_)return *this;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF)return _=1,*this;ch+=c;while((c=gc())!=EOF&&!isspace(c))ch+=c;if(c==EOF)_=1;return *this;}template<typename T>IN&operator>>(T&x){if(_)return *this;char c=gc();bool ff=0;while(c!=EOF&&(c<'0'||c>'9'))ff^=(c=='-'),c=gc();if(c==EOF){_=1;return *this;}x=0;while(c!=EOF&&'0'<=c&&c<='9')x=(x<<3)+(x<<1)+c-48,c=gc();if(c==EOF)_=1;if(ff)x=-x;return *this;}}in;struct OUT{char buf[str],*s,*t;OUT():s(buf),t(buf+str){}~OUT(){fwrite(buf,1,s-buf,stdout);}void pt(char c){(s==t)?(fwrite(s=buf,1,str,stdout),*s++=c):(*s++=c);}OUT&operator<<(const char*s){while(*s)pt(*s++);return *this;}OUT&operator<<(char*s){while(*s)pt(*s++);return *this;}OUT&operator<<(string s){for(int i=0;s[i];i++)pt(s[i]);return *this;}template<typename T>OUT&operator<<(T x){if(!x)return pt('0'),*this;if(x<0)pt('-'),x=-x;char a[30],t=0;while(x)a[t++]=x%10,x/=10;while(t--)pt(a[t]+'0');return *this;}}out;}using namespace IO;
#define N 100011
int a[N],n,m,A[N],B[N],f[N][20],fa[N][20],fb[N][20],P,Q;
struct node{
    int v,id;
    bool operator < (const node&x) const{
        return v<x.v;
    }
};
set<node>T;
void work(int p,int l){
    int i,j;
    P=Q=0;
    Fdr(i,19,0){
        if(f[p][i]&&P+Q+fa[p][i]+fb[p][i]<=l){
            P+=fa[p][i];
            Q+=fb[p][i];
            p=f[p][i];
        }
    }
    if(A[p]&&P+Q+fa[p][0]<=l)P+=fa[p][0];
}
int main(){
    in>>n;
    Fur(i,1,n)in>>a[i];
    T.insert(node{a[n],n});
    Fdr(i,n-1,1){
        set<node>::iterator it=T.lower_bound(node{a[i],i});
        node t1,t2;
        t1.v=t2.v=inf;
        t1.id=t2.id=0;
        if((*it).v>a[i]){
            t1=(*it);
            if(++it!=T.end())t2=*it;
            it--;
        }
        if(it!=T.begin()){
            node t=*--it;

            if(ABS(t.v-a[i])<ABS(t1.v-a[i]))t2=t1,t1=t;
            else if(ABS(t.v-a[i])==ABS(t1.v-a[i])&&t.v<t1.v)t2=t1,t1=t;
            else if(ABS(t.v-a[i])<ABS(t2.v-a[i]))t2=t;
            else if(ABS(t.v-a[i])==ABS(t2.v-a[i])&&t.v<t2.v)t2=t;

            if(it!=T.begin()){
                t=*--it;

                if(ABS(t.v-a[i])<ABS(t1.v-a[i]))t2=t1,t1=t;
                else if(ABS(t.v-a[i])==ABS(t1.v-a[i])&&t.v<t1.v)t2=t1,t1=t;
                else if(ABS(t.v-a[i])<ABS(t2.v-a[i]))t2=t;
                else if(ABS(t.v-a[i])==ABS(t2.v-a[i])&&t.v<t2.v)t2=t;
            }
        }
        B[i]=t1.id;A[i]=t2.id;
        T.insert(node{a[i],i});
    }
    Fur(i,1,n){
        f[i][0]=B[A[i]];
        fa[i][0]=ABS(a[i]-a[A[i]]);
        fb[i][0]=ABS(a[A[i]]-a[B[A[i]]]);
    }
    Fur(k,1,19)
        Fur(i,1,n){
            f[i][k]=f[f[i][k-1]][k-1];
            fa[i][k]=fa[i][k-1]+fa[f[i][k-1]][k-1];
            fb[i][k]=fb[i][k-1]+fb[f[i][k-1]][k-1];
        }
    int x,len,ans=0;
    db as=inf;
    in>>len;
    Fur(i,1,n){
        work(i,len);
        if(Q){
            if(1.0*P/Q<as)as=1.0*P/Q,ans=i;
        }
        else if(a[i]>a[ans]&&as==inf)ans=i;
    }
    out<<ans<<ln;
    in>>m;
    while(m--){
        in>>x>>len;
        work(x,len);
        out<<P<<" "<<Q<<ln;
    }
}
LG 1081 开车旅行
comment评论
Search
search