hdu 3605 Escape 状态压缩+最大流

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
using namespace std;

const int MAXN=100010;//点数的最大值
const int MAXM=400010;//边数的最大值
const int INF=0x3f3f3f3f;

struct Node
{
    int from,to,next;
    int cap;
}edge[MAXM];
int tol;
int head[MAXN];
int dep[MAXN];
int gap[MAXN];//gap[x]=y :说明残留网络中dep[i]==x的个数为y

int n;//n是总的点的个数，包括源点和汇点

void init()
{
    tol=0;
    memset(head,-1,sizeof(head));
}

void addedge(int u,int v,int w)
{
    edge[tol].from=u;
    edge[tol].to=v;
    edge[tol].cap=w;
    edge[tol].next=head[u];
    head[u]=tol++;
    edge[tol].from=v;
    edge[tol].to=u;
    edge[tol].cap=0;
    edge[tol].next=head[v];
    head[v]=tol++;
}
void BFS(int start,int end)
{
    memset(dep,-1,sizeof(dep));
    memset(gap,0,sizeof(gap));
    gap[0]=1;
    int que[MAXN];
    int front,rear;
    front=rear=0;
    dep[end]=0;
    que[rear++]=end;
    while(front!=rear)
    {
        int u=que[front++];
        if(front==MAXN)front=0;
        for(int i=head[u];i!=-1;i=edge[i].next)
        {
            int v=edge[i].to;
            if(dep[v]!=-1)continue;
            que[rear++]=v;
            if(rear==MAXN)rear=0;
            dep[v]=dep[u]+1;
            ++gap[dep[v]];
        }
    }
}
int SAP(int start,int end)
{
    int res=0;
    BFS(start,end);
    int cur[MAXN];
    int S[MAXN];
    int top=0;
    memcpy(cur,head,sizeof(head));
    int u=start;
    int i;
    while(dep[start]<n)
    {
        if(u==end)
        {
            int temp=INF;
            int inser;
            for(i=0;i<top;i++)
               if(temp>edge[S[i]].cap)
               {
                   temp=edge[S[i]].cap;
                   inser=i;
               }
            for(i=0;i<top;i++)
            {
                edge[S[i]].cap-=temp;
                edge[S[i]^1].cap+=temp;
            }
            res+=temp;
            top=inser;
            u=edge[S[top]].from;
        }
        if(u!=end&&gap[dep[u]-1]==0)//出现断层，无增广路
          break;
        for(i=cur[u];i!=-1;i=edge[i].next)
           if(edge[i].cap!=0&&dep[u]==dep[edge[i].to]+1)
             break;
        if(i!=-1)
        {
            cur[u]=i;
            S[top++]=i;
            u=edge[i].to;
        }
        else
        {
            int min=n;
            for(i=head[u];i!=-1;i=edge[i].next)
            {
                if(edge[i].cap==0)continue;
                if(min>dep[edge[i].to])
                {
                    min=dep[edge[i].to];
                    cur[u]=i;
                }
            }
            --gap[dep[u]];
            dep[u]=min+1;
            ++gap[dep[u]];
            if(u!=start)u=edge[S[--top]].from;
        }
    }
    return res;
}


int main()
{
    int i,j,c,N,m,s,t,a[2048],b,cnt;
    while(~scanf("%d%d",&N,&m))
    {
        init();
        s=0;
        n=1100+m+2;
        memset(a,0,sizeof(a));
        for(i=1; i<=N; i++)
        {
            t=0;
            for(j=1; j<=m; j++)
            {
                scanf("%d",&c);
                t*=2;
                if(c) t+=1;
            }
            a[t]++;
        }

        for(i=0;i<=1024;i++)
        {
            if(a[i]==0) continue;
            addedge(s,i,a[i]);
            c=i;
            cnt=m;
            while(c)
            {
                b=c%2;
                c/=2;
                if(b)
                {
                    addedge(i,cnt+1100,100000+5);
                    //printf("%d %d %d\n",i,cnt+1100,a[i]);
                }
                cnt--;
            }
        }

        for(i=1; i<=m; i++)
        {
            scanf("%d",&c);
            addedge(i+1100,n,c);
            //printf("%d %d\n",i+1100,c);
        }

        if(SAP(s,n)==N)
            printf("YES\n");
        else
            printf("NO\n");
    }
    return 0;
}

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<vector>
#include<queue>
using namespace std;

const int N=4048;
const int inf=1<<24;

struct Edge
{
    int from,to,cap,flow;
};

vector<Edge>edges;
vector<int>G[N];
int n,m,s,t;
int vis[N];
int d[N];
int cur[N];

void AddEdge(int from,int to,int cap)
{
    Edge tp;
    tp.from=from,tp.to=to,tp.cap=cap,tp.flow=0;
    edges.push_back(tp);

    tp.from=to,tp.to=from,tp.cap=0,tp.flow=0;
    edges.push_back(tp);

    int g_size=edges.size();
    G[from].push_back(g_size-2);
    G[to].push_back(g_size-1);
}

bool BFS()
{
    memset(vis,0,sizeof(vis));
    queue<int>Q;
    Q.push(s);
    d[s]=0;
    vis[s]=1;
    while(!Q.empty())
    {
        int x=Q.front();
        Q.pop();
        for(int i=0; i<G[x].size(); i++)
        {
            Edge &e=edges[G[x][i]];
            if(!vis[e.to]&&e.cap>e.flow)
            {
                vis[e.to]=1;
                d[e.to]=d[x]+1;
                Q.push(e.to);
            }
        }
    }
    return vis[t];
}

int DFS(int x,int a)
{
    if(x==t||a==0) return a;
    int flow=0,f;
    for(int &i=cur[x]; i<G[x].size(); i++)
    {
        Edge &e=edges[G[x][i]];
        if(d[x]+1==d[e.to]&&(f=DFS(e.to,min(a,e.cap-e.flow)))>0)
        {
            e.flow+=f;
            edges[G[x][i]^1].flow-=f;
            flow+=f;
            a-=f;
            if(a==0) break;
        }
    }
     if(!flow) d[x] = -1;
    return flow;
}

int Maxflow(int st,int ed)
{
    int flow=0;
    while(BFS())
    {
        memset(cur,0,sizeof(cur));
        flow+=DFS(st,inf);
        //printf("%d\n",flow);
    }
    return flow;
}


int main()
{
    int _,i,j,tn,cnt;
    int c,a[2048],b;
    while(~scanf("%d%d",&tn,&m))
    {
        edges.clear();
        for(i=0; i<N; i++)
            G[i].clear();

        s=1100+m+2;
        n=1100+m+1;
        memset(a,0,sizeof(a));
        for(i=1; i<=tn; i++)
        {
            t=0;
            for(j=1; j<=m; j++)
            {
                scanf("%d",&c);
                t*=2;
                if(c)
                    t+=1;
            }
            a[t]++;
        }

        for(i=0;i<=1024;i++)
        {
            if(a[i]==0) continue;
            AddEdge(s,i,a[i]);
            c=i;
            cnt=m;
            while(c)
            {
                b=c%2;
                c/=2;
                if(b)
                {
                    AddEdge(i,cnt+1100,100000+5);
                    //printf("%d %d %d\n",i,cnt+1100,a[i]);
                }
                cnt--;
            }
        }

        for(i=1; i<=m; i++)
        {
            scanf("%d",&c);
            AddEdge(i+1100,n,c);
            printf("%d %d\n",i+1100,c);
        }
        int ans=Maxflow(s,n);
        //printf("%d\n",ans);

        if(ans==tn)
            printf("YES\n");
        else
            printf("NO\n");
    }
    return 0;
}