[网络流24题] 试题库问题

题目链接：戳我
太水了啦
直接最大流跑输出即可。
代码如下：

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#define MAXN 100010
using namespace std;
struct Edge{int nxt,to;long long dis;}edge[MAXN<<2];
int head[MAXN<<1],dep[MAXN<<1],cur[MAXN<<1],c[MAXN<<1];
int n,m,s,t,edge_number=1;
long long tot=0;
inline void add(int from,int to,long long dis)
{
    edge[++edge_number].dis=dis;
    edge[edge_number].nxt=head[from];
    edge[edge_number].to=to;
    head[from]=edge_number;
}
inline bool bfs(int s,int t)
{
    queue<int>q;
    memset(dep,0x3f,sizeof(dep));
    memcpy(cur,head,sizeof(head));
    q.push(s);
    dep[s]=0;
    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        for(int i=head[u];i;i=edge[i].nxt)
        {
            int v=edge[i].to;
            if(dep[v]==0x3f3f3f3f&&edge[i].dis)
            {
                dep[v]=dep[u]+1;
                q.push(v);
            }
        }
    }
    if(dep[t]==0x3f3f3f3f) return false;
    return true;
}
inline long long dfs(int now,int t,long long minn)
{
    if(now==t||minn==0) return minn;
    long long flow=0,f;
    for(int i=cur[now];i;i=edge[i].nxt)
    {
        int v=edge[i].to;
        cur[now]=i;
        if(dep[v]==dep[now]+1&&(f=dfs(v,t,min(minn,edge[i].dis))))
        {
            flow+=f;
            minn-=f;
            edge[i].dis-=f;
            edge[i^1].dis+=f;
            if(!minn) break;
        }
    }
    return flow;
}
inline long long dinic(int s,int t)
{
    long long ans=0;
    while(bfs(s,t)) ans+=dfs(s,t,(long long)1e18);
    return ans;
}
int main()
{

    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++) scanf("%d",&c[i]),tot+=c[i];
    for(int i=1;i<=m;i++)
    {
        int p;
        scanf("%d",&p);
        for(int j=1;j<=p;j++)
        {
            int cur;
            scanf("%d",&cur);
            add(i,cur+m,1);
            add(cur+m,i,0);
        }
    }
    for(int i=1;i<=m;i++)
        add(0,i,1),add(i,0,0);
    for(int i=1;i<=n;i++)
        add(m+i,n+m+1,c[i]),add(n+m+1,m+i,0);

    if(dinic(0,n+m+1)<tot) printf("No Solution!
");
    else
    {
        for(int i=1+m;i<=m+n;i++)
        {
            printf("%d:",i-m);
            for(int j=head[i];j;j=edge[j].nxt)
            {
                if(edge[j].dis==1&&edge[j].to!=m+n+1)
                    printf(" %d",edge[j].to);
            }
            printf("
");
        }
    }
    return 0;
}