Flandre Scarlet's Blog

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先黑一个：开军旅行

大概因为两个人轮流艹做，很难想到倍增处理吧

但是说白了移动就是在一棵固定的树上跑罢了。

然后就能随手写了对不对w

倒是预处理不会机智的写法，map乱搞求指导：

SBCode：

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<set>
#include<map>
#include<vector>
#include<algorithm>
#define INF 5000000000LL
#define maxn 100010
using namespace std;
typedef long long LL;
LL H[maxn];
int n,TO[maxn][2],m;
int lca[maxn][19];
LL SA[maxn][19],SB[maxn][19];
map <int,LL>mp;
set <LL> S;
typedef set <LL> ::iterator ITER;
LL K[4];
LL Abs(LL a){return a<0?-a:a;}
int cmp(int a,int b)
{
	return abs(a)<abs(b);
}
double GG(int s,LL x,LL &sa,LL &sb)
{
	sa=sb=0;
	for (int j=18;j>=0;j--)
		if (lca[s][j]&&sa+sb+SA[s][j]+SB[s][j]<=x) sa+=SA[s][j],sb+=SB[s][j],s=lca[s][j];
	if (sb==0) return INF;
	return (double)sa/(double)sb;
}
int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;i++)
		scanf("%lld",&H[i]),mp[H[i]]=i;
	S.insert(H[n]);
	for (int i=n-1;i>=1;i--)
	{
		int l=0;
		ITER a=S.lower_bound(H[i]),b=S.upper_bound(H[i]);
		if (a!=S.begin()) a--,K[l++]=H[i]-(*a);
		if (a!=S.begin()) a--,K[l++]=H[i]-(*a);
		if (b!=S.end()) K[l++]=H[i]-(*b),b++;
		if (b!=S.end()) K[l++]=H[i]-(*b),b++;
		stable_sort(K,K+l,cmp);
		TO[i][1]=mp[H[i]-K[0]];
		if (l>1) TO[i][0]=mp[H[i]-K[1]];
		S.insert(H[i]);
	}
	for (int i=1;i<=n;i++) 
		lca[i][0]=TO[i][0],SA[i][0]=Abs(H[i]-H[TO[i][0]]);
	for (int i=1;i<=n;i++) 
		lca[i][1]=TO[lca[i][0]][1],SA[i][1]=SA[i][0],SB[i][1]=Abs(H[lca[i][0]]-H[lca[i][1]]);
	for (int j=2;j<=18;j++)
		for (int i=1;i<=n;i++)
			if (lca[lca[i][j-1]][j-1]) 
				lca[i][j]=lca[lca[i][j-1]][j-1],
				SA[i][j]=SA[i][j-1]+SA[lca[i][j-1]][j-1],
				SB[i][j]=SB[i][j-1]+SB[lca[i][j-1]][j-1];
	LL x0,sa,sb,ans;
	double mn=1e60;
	scanf("%lld",&x0);
	for (int i=1;i<=n;i++)
	{
		double t=GG(i,x0,sa,sb);
		if (t<mn||(t==mn&&H[i]>H[ans]))mn=t,ans=i;
	}
	printf("%lld\n",ans);
	scanf("%d",&m);
	for (int i=1;i<=m;i++)
	{
		int s;LL x;
		scanf("%d%lld",&s,&x);
		GG(s,x,sa,sb);
		printf("%lld %lld\n",sa,sb);
	}
	return 0;
}