bzoj2260&4349

只是为了贴上自己的朱刘算法模板

#include<bits/stdc++.h>
using namespace std;
const int N=102;
int b[N],mark[N],color[N],pre[N],ne;
double low[N],in[N];
struct edges{int u,v;double w;}e[N*N];
inline void addedge(int u,int v,double wi){e[++ne].u=u,e[ne].v=v,e[ne].w=wi;}
#define inf 0x7fffffff
inline double zhuliu(int rt,int n,int m){
	double res=0;
	while(1){
		int cnt,u,v;
		for(int i=0;i<=n;i++)in[i]=inf;
		for(int i=1;i<=m;i++)if(e[i].u!=e[i].v && in[e[i].v]>e[i].w)in[e[i].v]=e[i].w,pre[e[i].v]=e[i].u;
		for(int i=0;i<=n;i++)color[i]=mark[i]=0;
		in[rt]=cnt=0,mark[rt]=1;
		for(int i=1;i<=n;i++){
			res+=in[v=i];
			while(mark[v]!=i && !color[v] && v!=rt)mark[v]=i,v=pre[v];
			if(v!=rt && !color[v]){
				cnt++;
				for(u=pre[v];u!=v;u=pre[u])color[u]=cnt;
				color[v]=cnt;
			}
		}
		if(!cnt)break;
		for(int i=1;i<=n;i++)if(!color[i])color[i]=++cnt;
		int me=0;
		for(int i=1;i<=m;i++){
			v=e[i].v;
			e[i].u=color[e[i].u],e[i].v=color[e[i].v];
			if(e[i].u!=e[i].v)e[++me]=e[i],e[me].w-=in[v];
		}
		n=cnt,rt=color[rt],m=me;
	}
	return res;
}
int main(){
	int n;scanf("%d",&n);
	for(int i=1;i<=n;i++){scanf("%lf%d",&low[i],&b[i]);if(b[i])addedge(n+1,i,low[i]);else addedge(n+1,i,0);}
	int k,x,y;double z,ans;scanf("%d",&k);
	for(;k;k--){
		scanf("%d%d%lf",&x,&y,&z);
		if(b[x] && b[y])addedge(x,y,z),low[y]=min(low[y],z);
	}
	ans=zhuliu(n+1,n+1,ne);
	for(int i=1;i<=n;i++)if(b[i])ans+=(b[i]-1)*low[i];
	printf("%.2lf",ans);
	return 0;
}