BZOJ.5251.[八省联考2018]劈配mentor(最大流)

BZOJ
洛谷

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对于每个人，每次枚举一个志愿看是否能增广即可。
对于第二问，可以保留第一问中\(n\)次增广前后的\(n\)张图，二分，在对应图上看是否能增广即可。

貌似匈牙利的某种写法比网络流优多了...懒得看...
写的常数莫名大...

增广失败的话原图流量不会变啊，不用特意删掉新加的边，把表头head改了即可，而且判断是否能增广只需要判断BFS()是否返回1。

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Dinic：

//195228kb  6676ms
#include <cstdio>
#include <cctype>
#include <vector>
#include <cstring>
#include <algorithm>
#define gc() getchar()
typedef long long LL;
const int N=408,M=(N+40005)*2,INF=0x3f3f3f3f;

int T;
struct Graph
{
    int Enum,H[N],nxt[M],to[M],cap[M],cur[N],lev[N];
    inline void Init(int n)
    {
        Enum=1, memset(H,0,n+1<<2);
    }
    inline void AE(int u,int v,int w)
    {
        to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum, cap[Enum]=w;
        to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum, cap[Enum]=0;
    }
    bool BFS()
    {
        static int q[N];
        memset(lev,0,T+1<<2);
        int h=0,t=1; q[0]=0, lev[0]=1;
        while(h<t)
        {
            int x=q[h++];
            for(int i=H[x]; i; i=nxt[i])
                if(!lev[to[i]] && cap[i])
                {
                    q[t++]=to[i], lev[to[i]]=lev[x]+1;
                    if(to[i]==T) return 1;
                }
        }
        return 0;
    }
    int DFS(int x,int flow)
    {
        if(x==T) return flow;
        int used=0;
        for(int &i=cur[x]; i; i=nxt[i])
            if(lev[to[i]]==lev[x]+1 && cap[i])
            {
                int delta=DFS(to[i],std::min(flow,cap[i]));
                if(delta)
                {
                    cap[i]-=delta, cap[i^1]+=delta, used+=delta;
                    if(used==flow) return flow;
                }
            }
        return lev[x]=0,used;
    }
    void Dinic()
    {
        while(BFS()) memcpy(cur,H,T+1<<2), DFS(0,INF);
    }
}G[203];

inline int read()
{
    int now=0;register char c=gc();
    for(;!isdigit(c);c=gc());
    for(;isdigit(c);now=now*10+c-48,c=gc());
    return now;
}

int main()
{
    static int B[203],s[203],Ans1[203],tmpH[N];
    static std::vector<int> v[203][203];

    freopen("mentor.in","r",stdin);
    freopen("mentor.out","w",stdout);

    for(int Tests=read(),C=read(); Tests--; )
    {
        int n=read(),m=read(); T=n+m+1;
        G[0].Init(T);
        for(int i=1; i<=n; ++i) G[0].AE(0,i,1);
        for(int i=1; i<=m; ++i) G[0].AE(i+n,T,B[i]=read());
        for(int i=1; i<=n; ++i)
            for(int j=1; j<=m; ++j) v[i][j].clear();
        for(int i=1; i<=n; ++i)
            for(int j=1; j<=m; ++j) v[i][read()].push_back(j+n);
        for(int i=1; i<=n; ++i) s[i]=read();

        for(int i=1; i<=n; ++i)
        {
            G[i]=G[i-1];
            int j;
            for(j=1; j<=m; ++j)
            {
                std::vector<int> &vec=v[i][j];
                for(int k=0,l=vec.size(); k<l; ++k)  G[i].AE(i,vec[k],1);
                if(G[i].BFS()) {G[i].Dinic(); break;}
                if(vec.size()) G[i].Enum=G[i-1].Enum, memcpy(G[i].H,G[i-1].H,T+1<<2);
            }
            printf("%d ",Ans1[i]=j);
        }
        putchar('\n');
    
        for(int i=1; i<=n; ++i)
            if(Ans1[i]<=s[i]) putchar('0'), putchar(' ');
            else
            {
                int l=1,r=i-1,mid,ans=0,dream=s[i];
                while(l<=r)
                {
                    mid=l+r>>1;
                    int tmpEnum=G[mid-1].Enum;
                    memcpy(tmpH,G[mid-1].H,T+1<<2);
                    bool ok=0;
                    for(int j=1; j<=dream; ++j)
                    {
                        std::vector<int> &vec=v[i][j];
                        for(int k=0,l=vec.size(); k<l; ++k)  G[mid-1].AE(i,vec[k],1);
                        if(G[mid-1].BFS()) {ok=1; break;}
                    }
                    if(ok) ans=mid, l=mid+1;
                    else r=mid-1;
                    G[mid-1].Enum=tmpEnum, memcpy(G[mid-1].H,tmpH,T+1<<2);
                }
                printf("%d ",i-ans);
            }
        putchar('\n');
    }
    return 0;
}

ISAP：

//259320kb  7584ms
#include <cstdio>
#include <cctype>
#include <vector>
#include <cstring>
#include <algorithm>
#define gc() getchar()
typedef long long LL;
const int N=408,M=(N+40005)*2,INF=0x3f3f3f3f;

int T;
struct Graph
{
    int Enum,H[N],nxt[M],fr[M],to[M],cap[M],pre[N],lev[N];
    inline void Init(int n)
    {
        Enum=1, memset(H,0,n+1<<2);
    }
    inline void AE(int u,int v,int w)
    {
        to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum, fr[Enum]=u, cap[Enum]=w;
        to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum, fr[Enum]=v, cap[Enum]=0;
    }
    bool BFS()
    {
        static int q[N];
        const int lim=T+1;
        for(int i=0; i<T; ++i) lev[i]=lim;
        int h=0,t=1; q[0]=T, lev[T]=0;
        while(h<t)
        {
            int x=q[h++];
            for(int i=H[x]; i; i=nxt[i])
                if(cap[i^1] && lev[to[i]]==lim) q[t++]=to[i], lev[to[i]]=lev[x]+1;
        }
        return lev[0]<=T;
    }
    inline void Augment()
    {
//      int mn=INF;
//      for(int i=T; i; i=fr[pre[i]])
//          mn=std::min(mn,cap[pre[i]]);
        for(int i=T; i; i=fr[pre[i]])
            --cap[pre[i]], ++cap[pre[i]^1];
    }
    void ISAP()
    {
        static int cur[N],num[N];
        memset(num,0,T+1<<2);
        for(int i=0; i<=T; ++i) cur[i]=H[i], ++num[lev[i]];
        int x=0;
        while(lev[0]<=T)
        {
            if(x==T) x=0, Augment();
            bool can=0;
            for(int i=cur[x]; i; i=nxt[i])
                if(lev[to[i]]==lev[x]-1 && cap[i])
                {
                    can=1, cur[x]=i, pre[x=to[i]]=i;
                    break;
                }
            if(!can)
            {
                int mn=T;
                for(int i=H[x]; i; i=nxt[i])
                    if(cap[i]) mn=std::min(mn,lev[to[i]]);
                if(!--num[lev[x]]) break;
                ++num[lev[x]=mn+1], cur[x]=H[x];
                if(x) x=fr[pre[x]];
            }
        }
    }
}G[203];

inline int read()
{
    int now=0;register char c=gc();
    for(;!isdigit(c);c=gc());
    for(;isdigit(c);now=now*10+c-48,c=gc());
    return now;
}

int main()
{
    static int B[203],s[203],Ans1[203],tmpH[N];
    static std::vector<int> v[203][203];

    freopen("mentor.in","r",stdin);
    freopen("mentor.out","w",stdout);

    for(int Tests=read(),C=read(); Tests--; )
    {
        int n=read(),m=read(); T=n+m+1;
        G[0].Init(T);
        for(int i=1; i<=n; ++i) G[0].AE(0,i,1);
        for(int i=1; i<=m; ++i) G[0].AE(i+n,T,B[i]=read());
        for(int i=1; i<=n; ++i)
            for(int j=1; j<=m; ++j) v[i][j].clear();
        for(int i=1; i<=n; ++i)
            for(int j=1; j<=m; ++j) v[i][read()].push_back(j+n);
        for(int i=1; i<=n; ++i) s[i]=read();

        for(int i=1; i<=n; ++i)
        {
            G[i]=G[i-1];
            int j;
            for(j=1; j<=m; ++j)
            {
                std::vector<int> &vec=v[i][j];
                for(int k=0,l=vec.size(); k<l; ++k)  G[i].AE(i,vec[k],1);
                if(G[i].BFS()) {G[i].ISAP(); break;}
                if(vec.size()) G[i].Enum=G[i-1].Enum, memcpy(G[i].H,G[i-1].H,T+1<<2);
            }
            printf("%d ",Ans1[i]=j);
        }
        putchar('\n');
    
        for(int i=1; i<=n; ++i)
            if(Ans1[i]<=s[i]) putchar('0'), putchar(' ');
            else
            {
                int l=1,r=i-1,mid,ans=0,dream=s[i];
                while(l<=r)
                {
                    mid=l+r>>1;
                    int tmpEnum=G[mid-1].Enum;
                    memcpy(tmpH,G[mid-1].H,T+1<<2);
                    bool ok=0;
                    for(int j=1; j<=dream; ++j)
                    {
                        std::vector<int> &vec=v[i][j];
                        for(int k=0,l=vec.size(); k<l; ++k)  G[mid-1].AE(i,vec[k],1);
                        if(G[mid-1].BFS()) {ok=1; break;}
                    }
                    if(ok) ans=mid, l=mid+1;
                    else r=mid-1;
                    G[mid-1].Enum=tmpEnum, memcpy(G[mid-1].H,tmpH,T+1<<2);
                }
                printf("%d ",i-ans);
            }
        putchar('\n');
    }
    return 0;
}