2019 HDU 多校赛第二场 HDU 6598 Harmonious Army 最小割模型

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define INF 0x7ffffff
const int M = 200005;
struct ISAP {
	ll H[M],d[M],cur[M],pre[M],gap[M],Q[M];
	struct Edge {
		int u,v,c,n;
	} E[M];
	ll nv,flow,head,tail,cntE,f;
	void init() {
		cntE=0;
		memset(H,-1,sizeof(H));
	}
	void addedge(int u,int v,int c) {
		E[cntE]=Edge {u,v,c,H[u]};
		H[u]=cntE++;
		E[cntE]=Edge {v,u,0,H[v]};
		H[v]=cntE++;
	}
	void revbfs(int s,int t) {
		head=tail=0 ;
		memset(d,-1,sizeof(d));
		memset(gap,0,sizeof(gap));
		Q[tail++]=t;
		d[t]=0;
		gap[d[t]]=1;
		while (head!=tail) {
			int u=Q[head++];
			for (int i=H[u]; ~i; i=E[i].n) {
				int v=E[i].v;
				if (~d[v]) continue;
				d[v]=d[u]+1;
				gap[d[v]]++;
				Q[tail++]=v;
			}
		}
	}
	ll isap(int s,int t) {
		memcpy(cur,H,sizeof(cur));
		nv=t;
		flow=0;
		revbfs(s,t);
		int u=pre[s]=s,i;
		while (d[s]<nv) {
			if (u==t) {
				f=INF;
				for (i=s; i!=t; i=E[cur[i]].v)
					if (f>E[cur[i]].c) f=E[cur[i]].c,u=i;
				flow += f;
				for (i=s; i!=t; i=E[cur[i]].v)
					E[cur[i]].c-=f,E[cur[i]^1].c+=f;
			}
			for (i=cur[u]; ~i; i=E[i].n)
				if (E[i].c&&d[u]==d[E[i].v]+1) break ;
			if (~i) cur[u]=i,pre[E[i].v]=u,u=E[i].v;
			else            {
				if (0==--gap[d[u]]) break ;
				ll minv=nv,v;
				for (int i=H[u]; ~i; i=E[i].n) {
					v=E[i].v;
					if (E[i].c&&minv>d[v]) minv=d[v],cur[u]=i;
				}
				d[u]=minv+1;
				gap[d[u]]++;
				u=pre[u];
			}
		}
		return flow ;
	}
} isap;

int main() {
	int u,v,a,b,c;
	int n,m;
	while(~scanf("%d %d",&n,&m)) {
		isap.init();
		ll ans = 0;
		for(int i=1; i<=m; i++) {
			scanf("%d %d %d %d %d",&u,&v,&a,&b,&c);
			ans+=(a+b+c)*2;
			isap.addedge(n+1,u,5*a/4+c/3);
			isap.addedge(n+1,v,5*a/4+c/3);
			isap.addedge(u,n+2,a/4+4*c/3);
			isap.addedge(v,n+2,a/4+4*c/3);
			isap.addedge(u,v,a/2+c/3);
			isap.addedge(v,u,a/2+c/3);
		}
		ans-=isap.isap(n+1,n+2);
		printf("%lld\n",ans/2);
	}
	return 0;
}