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| #include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
template<typename T>inline void read(T &x)
{
char ch=getchar();
T f=1;
x=0;
while(!('0'<=ch&&ch<='9'))
{
if(ch=='-')
f=-1;
ch=getchar();
}
while('0'<=ch&&ch<='9')
{
x=(x<<3)+(x<<1)+ch-48;
ch=getchar();
}
x*=f;
}
const int N=100010,logN=20;
int n,m;
int head[N],nxt[N<<1],to[N<<1],w[N<<1],e;
int fa[N],son[N],dep[N],wt[N],sz[N],id[N],seq[N],top[N],cnt;
int st[N][logN][2],_log[N];
inline void add(int u,int v,int f)
{
to[++e]=v;
w[e]=f;
nxt[e]=head[u];
head[u]=e;
}
inline void build()
{
_log[0]=-1;
for(int i=1;i<=n;++i)
{
st[i][0][0]=st[i][0][1]=wt[seq[i]];
_log[i]=_log[i>>1]+1;
}
for(int j=1;j<=logN;++j)
{
for(int i=1;i+(1<<j)-1<=n;++i)
{
st[i][j][0]=max(st[i][j-1][0],st[i+(1<<j-1)][j-1][0]);
st[i][j][1]=min(st[i][j-1][1],st[i+(1<<j-1)][j-1][1]);
}
}
}
inline int qmax(int x,int y)
{
int s=_log[y-x+1];
return max(st[x][s][0],st[y-(1<<s)+1][s][0]);
}
inline int qmin(int x,int y)
{
int s=_log[y-x+1];
return min(st[x][s][1],st[y-(1<<s)+1][s][1]);
}
void dfs1(int x,int f,int d)
{
fa[x]=f;
dep[x]=d+1;
sz[x]=1;
for(int i=head[x];i;i=nxt[i])
{
int y=to[i];
if(y==f)
continue;
wt[y]=w[i];
dfs1(y,x,d+1);
sz[x]+=sz[y];
if(sz[y]>sz[son[x]])
son[x]=y;
}
}
void dfs2(int x,int t)
{
id[x]=++cnt;
top[x]=t;
seq[cnt]=x;
if(!son[x])
return;
dfs2(son[x],t);
for(int i=head[x];i;i=nxt[i])
{
int y=to[i];
if(y==fa[x]||y==son[x])
continue;
dfs2(y,y);
}
}
inline int querymin(int x,int y)
{
int ans=0x3f3f3f3f;
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])
swap(x,y);
ans=min(ans,qmin(id[top[x]],id[x]));
x=fa[top[x]];
}
if(dep[x]>dep[y])
swap(x,y);
if(x==y)
return ans;
return min(ans,qmin(id[x]+1,id[y]));
}
inline int querymax(int x,int y)
{
int ans=-0x3f3f3f3f;
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])
swap(x,y);
ans=max(ans,qmax(id[top[x]],id[x]));
x=fa[top[x]];
}
if(dep[x]>dep[y])
swap(x,y);
if(x==y)
return ans;
return max(ans,qmax(id[x]+1,id[y]));
}
int main()
{
read(n);
int u,v,f;
for(int i=1;i<n;++i)
{
read(u);
read(v);
read(f);
add(u,v,f);
add(v,u,f);
}
dfs1(1,1,1);
dfs2(1,1);
build();
read(m);
++m;
while(--m)
{
read(u);
read(v);
printf("%d %d\n",querymin(u,v),querymax(u,v));
}
return 0;
}
|