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| #include <bits/stdc++.h> #define MAXN 100005 using namespace std; inline int read(){ int x=0,f=1; char ch=getchar(); while (ch<'0'||ch>'9'){ if (ch=='-') f=-1; ch=getchar(); } while (ch>='0'&&ch<='9'){ x=(x<<3)+(x<<1)+(ch^'0'); ch=getchar(); } return x*f; } struct Edge{int to,len;}; vector<Edge>G[MAXN]; inline void AddEdge(int u,int v,int w){ Edge temp; temp.to=v; temp.len=w; G[u].push_back(temp); } int fa[MAXN],dep[MAXN],tofa[MAXN],dfn[MAXN],seq[MAXN],cnt,top[MAXN],sz[MAXN],son[MAXN]; void dfs1(int u,int father){ sz[u]=1; for (register int i=0;i<G[u].size();++i){ int v=G[u][i].to,w=G[u][i].len; if (v!=father){ fa[v]=u,dep[v]=dep[u]+1; tofa[v]=w; dfs1(v,u); sz[u]+=sz[v]; if (sz[v]>sz[son[u]]) son[u]=v; } } } void dfs2(int u,int t){ seq[dfn[u]=++cnt]=u; top[u]=t; if (son[u]) dfs2(son[u],t); else return ; for (register int i=0;i<G[u].size();++i){ int v=G[u][i].to; if (v!=son[u]&&v!=fa[u]){ dfs2(v,v); } } } namespace SegmentTree{ struct node{ int l,r; int maxn,mino; }tree[MAXN<<2]; #define lc i<<1 #define rc i<<1|1 inline void pushup(int i){ tree[i].maxn=max(tree[lc].maxn,tree[rc].maxn); tree[i].mino=min(tree[lc].mino,tree[rc].mino); } void Build(int i,int l,int r){ tree[i].l=l,tree[i].r=r; if (l==r){ tree[i].maxn=tree[i].mino=tofa[seq[l]]; return ; } int mid=(l+r)>>1; Build(lc,l,mid); Build(rc,mid+1,r); pushup(i); } int QueryMax(int i,int L,int R){ if (L<=tree[i].l&&tree[i].r<=R){ return tree[i].maxn; } int mid=(tree[i].l+tree[i].r)>>1,ans=-0x7fffffff; if (L<=mid) ans=max(ans,QueryMax(lc,L,R)); if (mid<R) ans=max(ans,QueryMax(rc,L,R)); return ans; } int QueryMin(int i,int L,int R){ if (L<=tree[i].l&&tree[i].r<=R){ return tree[i].mino; } int mid=(tree[i].l+tree[i].r)>>1,ans=0x7fffffff; if (L<=mid) ans=min(ans,QueryMin(lc,L,R)); if (mid<R) ans=min(ans,QueryMin(rc,L,R)); return ans; } } using namespace SegmentTree; inline int QueryChainMax(int u,int v){ int ans=-0x7fffffff; while (top[u]!=top[v]){ if (dep[top[u]]<dep[top[v]]) swap(u,v); ans=max(ans,QueryMax(1,dfn[top[u]],dfn[u])); u=fa[top[u]]; } if (u==v) return ans; if (dep[u]>dep[v]) swap(u,v); return max(ans,QueryMax(1,dfn[u]+1,dfn[v])); } inline int QueryChainMin(int u,int v){ int ans=0x7fffffff; while (top[u]!=top[v]){ if (dep[top[u]]<dep[top[v]]) swap(u,v); ans=min(ans,QueryMin(1,dfn[top[u]],dfn[u])); u=fa[top[u]]; } if (u==v) return ans; if (dep[u]>dep[v]) swap(u,v); return min(ans,QueryMin(1,dfn[u]+1,dfn[v])); } int main(){ int n=read(); for (register int i=1;i<n;++i){ int u=read(),v=read(),w=read(); AddEdge(u,v,w); AddEdge(v,u,w); } dfs1(1,0); dfs2(1,1); Build(1,1,n); int q=read(); while (q--){ int u=read(),v=read(); printf("%d %d\n",QueryChainMin(u,v),QueryChainMax(u,v)); } }
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