poj21516

首先对于一种商品

如果这种货不足需求就直接输出-1

剩下的就是KM算法

分k次分别计算每种商品的最小权值匹配

代码：

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
int n,m,k,shop[][],sup[][],cost[][][],edges[][],cntA,cntB;
int belongA[],belongB[],A[],B[],visA[],visB[],mat[],d;
int dfs(int i)
{
    visA[i]=;
    for (int j=;j<=cntB;j++)
     if (!visB[j]&&edges[i][j])
      {
        int t=edges[i][j]-A[i]-B[j];
        if (!t)
         {
            visB[j]=;
            if (!mat[j]||dfs(mat[j]))
              {
                mat[j]=i;
                return ;
             }
         }
        else d=min(d,t);
      }
    return ;
}
int match()
{
    memset(A,0x3f,sizeof(A));
    memset(B,,sizeof(B));
    for (int i=;i<=cntA;i++)
     for (int j=;j<=cntB;j++)A[i]=min(A[i],edges[i][j]);
    memset(mat,,sizeof(mat));
    for (int i=;i<=cntA;i++)
     {
        while ()
         {
            memset(visA,,sizeof(visA));
            memset(visB,,sizeof(visB));
            d=1e9;
            if (dfs(i))break;
            for (int j=;j<=cntA;j++)
             if (visA[j]) A[j]+=d;
            for (int j=;j<=cntB;j++)
             if (visB[j]) B[j]-=d;
         }
     }
    int ans=;
    for (int i=;i<=cntB;i++)ans+=edges[mat[i]][i];
    return ans;
}
int main()
{
    while (~scanf("%d%d%d",&n,&m,&k),n+m+k)
     {
        for (int i=;i<=n;i++)
         for (int j=;j<=k;j++)scanf("%d",&shop[i][j]);
        for (int i=;i<=m;i++)
         for (int j=;j<=k;j++)scanf("%d",&sup[i][j]);
        for (int t=;t<=k;t++)
         for (int i=;i<=n;i++)
          for (int j=;j<=m;j++)scanf("%d",&cost[t][i][j]);
        int flag=;
        for (int i=;i<=k;i++)
         {
            int need=,have=;
            for (int j=;j<=n;j++)need+=shop[j][i];
            for (int j=;j<=m;j++)have+=sup[j][i];
            if (need>have)
             {
                flag=;
                puts("-1");
                break;
             }
         }
        if (!flag)continue;
        int ans=;
        for (int t=;t<=k;t++)
         {
            cntA=cntB=;
            for (int i=;i<=n;i++)
             for (int j=;j<=shop[i][t];j++)belongA[++cntA]=i;
            for (int i=;i<=m;i++)
             for (int j=;j<=sup[i][t];j++)belongB[++cntB]=i;
            for (int i=;i<=cntA;i++)
             for (int j=;j<=cntB;j++)
              edges[i][j]=cost[t][belongA[i]][belongB[j]];
            ans+=match();
         }
        printf("%d\n",ans);
    }
    return ;
}