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| #include <bits/stdc++.h> #define MAXN 40005 #define MAXM 23 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>G1[MAXN],G2[MAXN]; inline void _AddEdge1(int u,int v,int w){ G1[u].push_back(Edge{v,w}); } inline void AddEdge1(int u,int v,int w){ _AddEdge1(u,v,w),_AddEdge1(v,u,w); } inline void _AddEdge2(int u,int v,int w){ G2[u].push_back(Edge{v,w}); } inline void AddEdge2(int u,int v,int w){ _AddEdge2(u,v,w),_AddEdge2(v,u,w); } namespace Lca{ int anc[MAXN][MAXM],dis[MAXN],dep[MAXN]; void dfs(int u,int father){ anc[u][0]=father; for (register int i=1;i<MAXM;++i){ anc[u][i]=anc[anc[u][i-1]][i-1]; } for (register int i=0;i<G2[u].size();++i){ int v=G2[u][i].to,w=G2[u][i].len; if (v!=father){ dep[v]=dep[u]+1; dis[v]=dis[u]+w; dfs(v,u); } } } inline int LCA(int u,int v){ if (dep[u]<dep[v]) swap(u,v); for (register int i=MAXM-1;i>=0;--i){ if (dep[anc[u][i]]>=dep[v]){ u=anc[u][i]; } } if (u==v){ return v; } for (register int i=MAXM-1;i>=0;--i){ if (anc[u][i]!=anc[v][i]){ u=anc[u][i]; v=anc[v][i]; } } return anc[u][0]; } inline int Jump(int u,int lca){ for (register int i=MAXM-1;i>=0;--i){ if (dep[anc[u][i]]>dep[lca]){ u=anc[u][i]; } } return u; } inline int Dis(int u,int v){ return dis[u]+dis[v]-dis[LCA(u,v)]*2; } } using namespace Lca; int square; int sum[MAXN]; namespace RS_Tree{ int dfn[MAXN],low[MAXN],cnt,fa[MAXN],tofa[MAXN]; void tarjan(int u,int father){ dfn[u]=low[u]=++cnt; for (register int i=0;i<G1[u].size();++i){ int v=G1[u][i].to,w=G1[u][i].len; if (v!=father){ if (!dfn[v]){fa[v]=u;tofa[v]=w;tarjan(v,u);low[u]=min(low[u],low[v]);} else{low[u]=min(low[u],dfn[v]);} if (low[v]<=dfn[u]) continue; AddEdge2(u,v,w); } } for (register int i=0;i<G1[u].size();++i){ int v=G1[u][i].to; if (fa[v]==u||dfn[v]<=dfn[u]) continue; ++square; int s=G1[u][i].len,t=v; while (t!=fa[u]){ sum[t]=s; s+=tofa[t]; t=fa[t]; } sum[square]=sum[u];sum[u]=0; t=v; while (t!=fa[u]){ AddEdge2(t,square,min(sum[t],sum[square]-sum[t])); t=fa[t]; } } } } using namespace RS_Tree; int n,m; int main(){ n=read(),m=read(); int q=read(); for (register int i=1;i<=m;++i){ int u=read(),v=read(),w=read(); AddEdge1(u,v,w); } square=n; tarjan(1,0); dfs(1,1); while (q--){ int u=read(),v=read(); int lca=LCA(u,v); if (lca<=n){ printf("%d\n",Dis(u,v)); } else { int A=Jump(u,lca),B=Jump(v,lca); int ans=Dis(u,A)+Dis(B,v); if (sum[A]<sum[B]) swap(A,B); printf("%d\n",ans+min(sum[A]-sum[B],sum[lca]+sum[B]-sum[A])); } } }
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