标签:http def pair while fir space return org end
https://www.luogu.org/problem/P4716
#include<bits/stdc++.h> #define ll long long #define rep(ii,a,b) for(int ii=a;ii<=b;++ii) #define per(ii,a,b) for(int ii=b;ii>=a;--ii) #define forn(i,x,g,e) for(int i=g[x];i;i=e[i].next) #define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) #define ull unsigned long long #define fi first #define se second #define mp make_pair #define pii pair<ll,ll> #define all(x) x.begin(),x.end() #define show(x) cout<<#x<<"="<<x<<endl #define showa(a,b) cout<<#a<<‘[‘<<b<<"]="<<a[b]<<endl #define show2(x,y) cout<<#x<<"="<<x<<" "<<#y<<"="<<y<<endl #define show3(x,y,z) cout<<#x<<"="<<x<<" "<<#y<<"="<<y<<" "<<#z<<"="<<z<<endl #define show4(w,x,y,z) cout<<#w<<"="<<w<<" "<<#x<<"="<<x<<" "<<#y<<"="<<y<<" "<<#z<<"="<<z<<endl #define show5(v,w,x,y,z) cout<<#v<<"="<<v<<" "<<#w<<"="<<w<<" "<<#x<<"="<<x<<" "<<#y<<"="<<y<<" "<<#z<<"="<<z<<endl #define showa2(x,a,b) cout<<#x<<": ";rep(i,a,b) cout<<x[i]<<‘ ‘;cout<<endl using namespace std;//head const int maxn=1e3+10,maxm=1e4+10; const ll INF=0x3f3f3f3f,mod=1e9+7; int casn,n,m,k; struct node{int a,b,c;}e[maxm]; int in[maxn],pre[maxn],vis[maxn],id[maxn]; ll mag(){ ll ans=0;int cnt=0,a,b,laz; while(1){ rep(i,1,n) in[i]=INF,id[i]=vis[i]=0; rep(i,1,m) if(e[i].a^e[i].b&&e[i].c<in[e[i].b]) pre[e[i].b]=e[i].a,in[e[i].b]=e[i].c; in[k]=0; rep(i,1,n){ if(in[i]==INF) return -1; ans+=in[i]; for(a=i;a^k&&vis[a]^i&&!id[a];a=pre[a])vis[a]=i; if(a^k&&!id[a]){ id[a]=++cnt; for(b=pre[a];a^b;b=pre[b])id[b]=cnt; } } if(!cnt) return ans; rep(i,1,n) if(!id[i]) id[i]=++cnt; rep(i,1,m) { laz=in[e[i].b]; if((e[i].a=id[e[i].a])^(e[i].b=id[e[i].b])) e[i].c-=laz; } n=cnt;k=id[k],cnt=0; } } int main() {IO; cin>>n>>m>>k; rep(i,1,m)cin>>e[i].a>>e[i].b>>e[i].c; cout<<mag()<<endl; }
标签:http def pair while fir space return org end
原文地址:https://www.cnblogs.com/nervendnig/p/11625479.html