POJ 2060 Taxi Cab Scheme（最小路径覆盖）

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
const int MAX_N=510;

int T,n,total;
int st[MAX_N],end[MAX_N],vis[MAX_N],match[MAX_N],head[MAX_N];
int a[MAX_N],b[MAX_N],c[MAX_N],d[MAX_N];

struct Edge{
int to,next;

Edge () {}
Edge(int to,int next) : to(to),next(next) {
}
}edge[MAX_N*MAX_N];

inline void AddEdge(int from,int to)
{
edge[total].to=to;
edge[total].next=head[from];
head[from]=total++;
}

inline bool dfs(int u)
{
for(int i=head[u];i!=-1;i=edge[i].next){
int v=edge[i].to;
if(!vis[v]){
vis[v]=1;
if(match[v]==-1 || dfs(match[v])){
match[v]=u;
return true;
}
}
}
return false;
}

inline void solve()
{
memset(match,-1,sizeof(match));
int res=0;
for(int i=1;i<=n;i++){
memset(vis,0,sizeof(vis));
if(dfs(i)){
res++;
}
}
printf("%d\n",n-res);
}

int main()
{
scanf("%d",&T);
while(T--){
scanf("%d",&n);
for(int i=1;i<=n;i++){
char s[10];
scanf("%s%d%d%d%d",s,&a[i],&b[i],&c[i],&d[i]);
st[i]=(s[1]-'0')*60;
st[i]+=(s[0]-'0')*600;
st[i]+=s[4]-'0';
st[i]+=(s[3]-'0')*10;
end[i]=st[i]+abs(a[i]-c[i])+abs(b[i]-d[i]);
}
memset(head,-1,sizeof(head));
total=0;
for(int i=1;i<=n;i++){
for(int j=i+1;j<=n;j++){
if(end[i]+abs(c[i]-a[j])+abs(d[i]-b[j])<st[j]){
AddEdge(i,j);
}
}
}
solve();
}
return 0;
}