先Floyd求牛到机器最短距离，然后二分枚举最长的边。
#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
using namespace std;
#define INF (1<<30)
#define MAXN 233
#define MAXM 233*233*20 struct Edge{
int v,cap,flow,next;
}edge[MAXM];
int vs,vt,NE,NV;
int head[MAXN]; void addEdge(int u,int v,int cap){
edge[NE].v=v; edge[NE].cap=cap; edge[NE].flow=;
edge[NE].next=head[u]; head[u]=NE++;
edge[NE].v=u; edge[NE].cap=; edge[NE].flow=;
edge[NE].next=head[v]; head[v]=NE++;
} int level[MAXN];
int gap[MAXN];
void bfs(){
memset(level,-,sizeof(level));
memset(gap,,sizeof(gap));
level[vt]=;
gap[level[vt]]++;
queue<int> que;
que.push(vt);
while(!que.empty()){
int u=que.front(); que.pop();
for(int i=head[u]; i!=-; i=edge[i].next){
int v=edge[i].v;
if(level[v]!=-) continue;
level[v]=level[u]+;
gap[level[v]]++;
que.push(v);
}
}
} int pre[MAXN];
int cur[MAXN];
int ISAP(){
bfs();
memset(pre,-,sizeof(pre));
memcpy(cur,head,sizeof(head));
int u=pre[vs]=vs,flow=,aug=INF;
gap[]=NV;
while(level[vs]<NV){
bool flag=false;
for(int &i=cur[u]; i!=-; i=edge[i].next){
int v=edge[i].v;
if(edge[i].cap!=edge[i].flow && level[u]==level[v]+){
flag=true;
pre[v]=u;
u=v;
//aug=(aug==-1?edge[i].cap:min(aug,edge[i].cap));
aug=min(aug,edge[i].cap-edge[i].flow);
if(v==vt){
flow+=aug;
for(u=pre[v]; v!=vs; v=u,u=pre[u]){
edge[cur[u]].flow+=aug;
edge[cur[u]^].flow-=aug;
}
//aug=-1;
aug=INF;
}
break;
}
}
if(flag) continue;
int minlevel=NV;
for(int i=head[u]; i!=-; i=edge[i].next){
int v=edge[i].v;
if(edge[i].cap!=edge[i].flow && level[v]<minlevel){
minlevel=level[v];
cur[u]=i;
}
}
if(--gap[level[u]]==) break;
level[u]=minlevel+;
gap[level[u]]++;
u=pre[u];
}
return flow;
} int d[MAXN][MAXN],k,c,m,N;
bool available(int mx){
memset(head,-,sizeof(head));
for(int i=; i<=k; ++i) addEdge(i,vt,m);
for(int i=; i<=c; ++i) addEdge(vs,i+k,);
for(int i=; i<=c; ++i){
for(int j=; j<=k; ++j){
if(d[i+k][j]== || d[i+k][j]>mx) continue;
addEdge(i+k,j,);
}
}
return ISAP()==c;
}
inline void floyd(){
for(int k=; k<=N; ++k){
for(int i=; i<=N; ++i){
if(!d[i][k]) continue;
for(int j=; j<=N; ++j){
if(d[k][j] && (d[i][j]== || d[i][j]>d[i][k]+d[k][j])) d[i][j]=d[i][k]+d[k][j];
}
}
}
}
int main(){
scanf("%d%d%d",&k,&c,&m);
N=k+c; vs=; vt=N+; NV=vt+; for(int i=; i<=N; ++i){
for(int j=; j<=N; ++j) scanf("%d",&d[i][j]);
}
floyd(); int l=,r=INF;
while(l<r){
int mid=l+r>>;
if(available(mid)) r=mid;
else l=mid+;
}
printf("%d",l);
return ;
}