#include "graph_tree/push_relabel.hpp"
#pragma once #include<vector> #include<cmath> #include<queue> #include<tuple> /** * @brief 最大流(push_relabel法O(V^2√E)) */ template<typename T> class push_relabel{ int n; T f=0; using i64=long long; struct edge{ int from,to,rev; T flow,cap; }; std::vector<i64>h,d; std::vector<std::vector<edge*>>g; std::vector<size_t>seen; std::priority_queue<std::pair<i64,int>,std::vector<std::pair<i64,int>>,std::greater<std::pair<i64,int>>>que; public: push_relabel(int n):n(n){ h.resize(n,0); d.resize(n,0); g.resize(n); seen.resize(n,0); } void add_edge(int u,int v,T cap){ g[u].emplace_back(new edge{u,v,(int)g[v].size(),0,cap}); g[v].emplace_back(new edge{v,u,(int)g[u].size()-1,0,0}); } void push(edge* e){ int u=e->from,v=e->to; i64 df=std::min(d[u],e->cap-e->flow); e->flow+=df; g[v][e->rev]->flow-=df; d[u]-=df; d[v]+=df; if(d[v]>0)que.emplace(h[v],v); if(d[u]>0)que.emplace(h[u],u); } void relabel(int u){ i64 mn=n*2; for(edge* e:g[u]){ if(e->cap-e->flow>0){ mn=std::min(mn,h[e->to]); } } h[u]=1+mn; que.emplace(h[u],u); } void discharge(int u){ while(d[u]>0){ if(seen[u]<g[u].size()){ edge* e=g[u][seen[u]]; if(e->cap-e->flow>0 && h[u]==h[e->to]+1){ push(e); }else{ seen[u]+=1; } }else{ relabel(u); seen[u]=0; } } } T run(int s,int t){ h[s]=n; for(auto e:g[s]){ d[s]+=e->cap; push(e); } while(!que.empty()){ int u=que.top().second; que.pop(); if(u==s||u==t)continue; discharge(u); } for(auto e:g[s])f+=e->flow; return f; } };
#line 2 "graph_tree/push_relabel.hpp" #include<vector> #include<cmath> #include<queue> #include<tuple> /** * @brief 最大流(push_relabel法O(V^2√E)) */ template<typename T> class push_relabel{ int n; T f=0; using i64=long long; struct edge{ int from,to,rev; T flow,cap; }; std::vector<i64>h,d; std::vector<std::vector<edge*>>g; std::vector<size_t>seen; std::priority_queue<std::pair<i64,int>,std::vector<std::pair<i64,int>>,std::greater<std::pair<i64,int>>>que; public: push_relabel(int n):n(n){ h.resize(n,0); d.resize(n,0); g.resize(n); seen.resize(n,0); } void add_edge(int u,int v,T cap){ g[u].emplace_back(new edge{u,v,(int)g[v].size(),0,cap}); g[v].emplace_back(new edge{v,u,(int)g[u].size()-1,0,0}); } void push(edge* e){ int u=e->from,v=e->to; i64 df=std::min(d[u],e->cap-e->flow); e->flow+=df; g[v][e->rev]->flow-=df; d[u]-=df; d[v]+=df; if(d[v]>0)que.emplace(h[v],v); if(d[u]>0)que.emplace(h[u],u); } void relabel(int u){ i64 mn=n*2; for(edge* e:g[u]){ if(e->cap-e->flow>0){ mn=std::min(mn,h[e->to]); } } h[u]=1+mn; que.emplace(h[u],u); } void discharge(int u){ while(d[u]>0){ if(seen[u]<g[u].size()){ edge* e=g[u][seen[u]]; if(e->cap-e->flow>0 && h[u]==h[e->to]+1){ push(e); }else{ seen[u]+=1; } }else{ relabel(u); seen[u]=0; } } } T run(int s,int t){ h[s]=n; for(auto e:g[s]){ d[s]+=e->cap; push(e); } while(!que.empty()){ int u=que.top().second; que.pop(); if(u==s||u==t)continue; discharge(u); } for(auto e:g[s])f+=e->flow; return f; } };