KM算法的应用

时间：2023-03-09 19:17:44
KM算法的应用

HDU2255 模板     难度x

HDU2282 思维     难度XXx

HDU3722 模板     难度X

HDU3395 模版

HDU1533 最小值模型 难度x

HDU2853

HDU3523

HDU1533

HDU3488

HDU2448 +最短路

HDU2255

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

#include<algorithm>

using namespace std;

const int maxn=;

const int inf=0x7ffffff;

int map[maxn][maxn];

int vis1[maxn],vis2[maxn];

int ex1[maxn],ex2[maxn];

int lack[maxn];

int link[maxn];

int ans,n;

bool _bfs(int v)

{

    vis1[v]=true;

    for(int i=;i<=n;i++){

        if(!vis2[i]){

            int tmp=ex1[v]+ex2[i]-map[v][i];

            if(tmp==){

              vis2[i]=true;

              if(!link[i]||_bfs(link[i])){

                 link[i]=v;

                 return true;

              }

            }

            else if(tmp<lack[i]) lack[i]=tmp;

        }

    }

    return false;

}

void _KM()

{

    int t,i,j;

    memset(link,,sizeof(link));

    memset(ex2,,sizeof(ex2));

    for(i=;i<=n;i++){

        ex1[i]=map[i][];

        for(j=;j<=n;j++)

         if(ex1[i]<map[i][j]) ex1[i]=map[i][j];

    }

    for(t=;t<=n;t++){

        for(i=;i<=n;i++) lack[i]=inf;//思考：为什么在这里？

        while(true){

            memset(vis1,,sizeof(vis1));

            memset(vis2,,sizeof(vis2));

            if(_bfs(t))  break;

            int gap=inf;

            for(i=;i<=n;i++)

             if(!vis2[i]&&lack[i]<gap) gap=lack[i];

            for(i=;i<=n;i++) if(vis1[i]) ex1[i]-=gap;

            for(i=;i<=n;i++) if(vis2[i]) ex2[i]+=gap;

            for(i=;i<=n;i++) if(!vis2[i])lack[i]-=gap;

        }

    }

    ans=;

    for(i=;i<=n;i++) ans+=map[link[i]][i];

    printf("%d\n",ans);

}

int main()

{

    int i,j;

    while(~scanf("%d",&n)){

        for(i=;i<=n;i++)

         for(j=;j<=n;j++) scanf("%d",&map[i][j]);

        _KM();

    }

    return ;

} 
HDU1533

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

#include<algorithm>

#include<cmath>

using namespace std;

const int maxn=;

const int inf=0x7ffffff;

int map[maxn][maxn];

int vis1[maxn],vis2[maxn];

int ex1[maxn],ex2[maxn];

int lack[maxn];

int link[maxn];

int ans,n;

int x1[maxn],x2[maxn],y[maxn],y2[maxn];

int Abs(int v){

    if(v<) v=-v;

    return v;

}

bool _bfs(int v)

{

    vis1[v]=true;

    for(int i=;i<=n;i++){

        if(!vis2[i]){

            int tmp=ex1[v]+ex2[i]-map[v][i];

            if(tmp==){

              vis2[i]=true;

              if(!link[i]||_bfs(link[i])){

                 link[i]=v;

                 return true;

              }

            }

            else if(tmp<lack[i]) lack[i]=tmp;

        }

    }

    return false;

}

void _KM()

{

    int t,i,j;

    memset(link,,sizeof(link));

    memset(ex2,,sizeof(ex2));

    for(i=;i<=n;i++){

        ex1[i]=map[i][];

        for(j=;j<=n;j++)

         if(ex1[i]<map[i][j]) ex1[i]=map[i][j];

    }

    for(t=;t<=n;t++){

        for(i=;i<=n;i++) lack[i]=inf;//思考：为什么在这里？

        while(true){

            memset(vis1,,sizeof(vis1));

            memset(vis2,,sizeof(vis2));

            if(_bfs(t))  break;

            int gap=inf;

            for(i=;i<=n;i++)

             if(!vis2[i]&&lack[i]<gap) gap=lack[i];

            for(i=;i<=n;i++) if(vis1[i]) ex1[i]-=gap;

            for(i=;i<=n;i++) if(vis2[i]) ex2[i]+=gap;

            for(i=;i<=n;i++) if(!vis2[i])lack[i]-=gap;

        }

    }

    ans=;

    for(i=;i<=n;i++)

       ans-=map[link[i]][i];

    ans=ans;

    printf("%d\n",ans);

}

int main()

{

    int i,j,m,cnt1,cnt2;

    char c;

    while(~scanf("%d%d",&n,&m)){

        if(n==&&m==) return ;

        cnt1=cnt2=;

        for(i=;i<=n;i++)

         for(j=;j<=m;j++) {

                cin>>c;

                if(c=='H') {

                    x1[++cnt1]=i;y[cnt1]=j;

                }

                if(c=='m'){

                    x2[++cnt2]=i;y2[cnt2]=j;

                }

         }

         n=cnt1;

         for(i=;i<=n;i++)

          for(j=;j<=n;j++){

                map[i][j]=-(Abs(x1[i]-x2[j])+Abs(y[i]-y2[j]));

          }

        _KM();

    }

    return ;

} 
HDU2282

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

#include<algorithm>

#include<cmath>

using namespace std;

const int maxn=;

const int inf=0x7ffffff;

int map[maxn][maxn];

int vis1[maxn],vis2[maxn];

int ex1[maxn],ex2[maxn];

int lack[maxn];

int link[maxn];

int ans,n;

int x[maxn],p[maxn],y[maxn],cnt1,cnt2;

int Abs(int v){

    if(v<) v=-v;

    return v;

}

bool _bfs(int v)

{

    vis1[v]=true;

    for(int i=;i<=cnt2;i++){

        if(!vis2[i]){

            int tmp=ex1[v]+ex2[i]-map[v][i];

            if(tmp==){

              vis2[i]=true;

              if(!link[i]||_bfs(link[i])){

                 link[i]=v;

                 return true;

              }

            }

            else if(tmp<lack[i]) lack[i]=tmp;

        }

    }

    return false;

}

void _KM()

{

    int t,i,j;

    memset(link,,sizeof(link));

    memset(ex2,,sizeof(ex2));

    for(i=;i<=cnt1;i++){

        ex1[i]=map[i][];

        for(j=;j<=cnt2;j++)

         if(ex1[i]<map[i][j]) ex1[i]=map[i][j];

    }

    for(t=;t<=cnt1;t++){

        for(i=;i<=cnt2;i++) lack[i]=inf;//思考：为什么在这里？

        while(true){

            memset(vis1,,sizeof(vis1));

            memset(vis2,,sizeof(vis2));

            if(_bfs(t))  break;

            int gap=inf;

            for(i=;i<=cnt2;i++)

             if(!vis2[i]&&lack[i]<gap) gap=lack[i];

            for(i=;i<=cnt1;i++) if(vis1[i]) ex1[i]-=gap;

            for(i=;i<=cnt2;i++) if(vis2[i]) ex2[i]+=gap;

            for(i=;i<=cnt2;i++) if(!vis2[i])lack[i]-=gap;

        }

    }

    ans=;

    for(i=;i<=cnt2;i++)

       ans-=map[link[i]][i];

    printf("%d\n",ans);

}

int main()

{

    int i,j,m;

    char c;

    while(~scanf("%d",&n)){

        memset(map,,sizeof(map));

        cnt1=cnt2=;

        for(i=;i<=n;i++) scanf("%d",&p[i]);

        for(i=;i<=n;i++){

           while(p[i]>) {

             x[++cnt1]=i;

             p[i]--;

           }

           if(p[i]==) y[++cnt2]=i;

        }

        for(i=;i<=cnt1;i++)

         for(j=;j<=cnt2;j++)

          map[i][j]=-min(Abs(x[i]-y[j]),n-Abs(x[i]-y[j]));

        _KM();

    }

    return ;

} 
HDU3722

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

#include<algorithm>

#include<cmath>

#include<cstring>

#include<string>

#include<string.h>

using namespace std;

const int maxn=;

const int inf=0x7ffffff;

char c[][];

int map[maxn][maxn];

int vis1[maxn],vis2[maxn];

int ex1[maxn],ex2[maxn];

int lack[maxn];

int link[maxn];

int ans,n;

int x1[maxn],x2[maxn],y[maxn],y2[maxn];

int _get(int u,int v){

    int i,j=,L1=strlen(c[u]+),L2=strlen(c[v]+);

    for(i=L1;i>=;i--){

        j++;

        if(j>L2||c[u][i]!=c[v][j]){

            j--;break;

        }

    }

    return j;

}

bool _bfs(int v)

{

    vis1[v]=true;

    for(int i=;i<=n;i++){

        if(!vis2[i]){

            int tmp=ex1[v]+ex2[i]-map[v][i];

            if(tmp==){

              vis2[i]=true;

              if(!link[i]||_bfs(link[i])){

                 link[i]=v;

                 return true;

              }

            }

            else if(tmp<lack[i]) lack[i]=tmp;

        }

    }

    return false;

}

void _KM()

{

    int t,i,j;

    memset(link,,sizeof(link));

    memset(ex2,,sizeof(ex2));

    for(i=;i<=n;i++){

        ex1[i]=map[i][];

        for(j=;j<=n;j++)

         if(ex1[i]<map[i][j]) ex1[i]=map[i][j];

    }

    for(t=;t<=n;t++){

        for(i=;i<=n;i++) lack[i]=inf;

        while(true){

            memset(vis1,,sizeof(vis1));

            memset(vis2,,sizeof(vis2));

            if(_bfs(t))  break;

            int gap=inf;

            for(i=;i<=n;i++)

             if(!vis2[i]&&lack[i]<gap) gap=lack[i];

            for(i=;i<=n;i++) if(vis1[i]) ex1[i]-=gap;

            for(i=;i<=n;i++) if(vis2[i]) ex2[i]+=gap;

            for(i=;i<=n;i++) if(!vis2[i])lack[i]-=gap;

        }

    }

    ans=;

    for(i=;i<=n;i++)

       ans+=map[link[i]][i];

    ans=ans;

    printf("%d\n",ans);

}

int main()

{

    int i,j;

    while(~scanf("%d",&n)){

        for(i=;i<=n;i++) scanf("%s",c[i]+);

        for(i=;i<=n;i++)

         for(j=;j<=n;j++){

             if(i==j) map[i][j]=;

             else     map[i][j]=_get(i,j)；

         }

        _KM();

    }

    return ;

}

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