Dinic92分求助
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Dinic92分求助
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黑影洞人楼主2022/8/10 20:47
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue> 
#define inf 214748364700000000
#define N 1919810
#define p 6767
#define int long long
using namespace std;
int head[N],to[N],nxt[N],val[N],n,m,d[N],s,t,tot=1;
void add(int u,int v,int w){
	to[++tot]=v;
	nxt[tot]=head[u];
	head[u]=tot;
	val[tot]=w;
}
bool bfs(){
	memset(d,-1,sizeof(d));
	queue<int>q;
	q.push(s);
	d[s]=0;
	while(!q.empty()){
		int x=q.front();q.pop();
		for(int i=head[x];i;i=nxt[i]){
			if(!val[i])continue;
			int y=to[i];
			if(d[y]==-1){
				d[y]=d[x]+1;
				if(y==t)return 1;
				q.push(y);
			}
		}
	}
	return 0; 
}
int dfs(int x,int a){
	if(!a||x==t)return a;
	int res=a;
	for(int i=head[x];i;i=nxt[i]){
		int y=to[i];
		if(val[i]&&d[x]+1==d[y]){
			int tmp=dfs(y,min(val[i],res));
			res-=tmp;
			val[i]-=tmp;
			val[i^1]+=tmp;
			if(res==0)return a;
		}
	}
	if(res==a)d[x]=-1;
	return a-res;
}
int dinic(){
	int flow=0;
	while(bfs())flow+=dfs(s,inf);
	return flow;
}
signed main(){
	scanf("%lld%lld",&n,&m);
	s=1,t=n;
	for(int i=1;i<=m;i++){
		int a,b,c;
		scanf("%lld%lld%lld",&a,&b,&c);
		add(a,b,c*p+1);
		add(b,a,0);
	}
	int ans=dinic();
	printf("%lld %lld",ans/p,ans%p);
	return 0;
}

(验证码tntt祭)

2022/8/10 20:47
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