hdu2389-二分匹配HK算法

#include<iostream>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<queue>
using namespace std;
const int mx = 3005;
const int inf = 0x3f3f3f3f;
int dx[mx],dy[mx],dis,n,m;
int vis[mx],x[mx],y[mx];
bool g[mx][mx];
double T;
struct pos{
double x,y,s;
}a[mx],b[mx];
bool search(){
queue<int>q;
dis = inf;
memset(dx,-1,sizeof(dx));
memset(dy,-1,sizeof(dy));
for(int i = 0; i < n; i ++)
if(x[i] == -1){
q.push(i);
dx[i] = 0;
}
while(!q.empty()){
int u = q.front();
if(dx[u] > dis)    break;
q.pop();
for(int v = 0; v < m; v++){
if(g[u][v] && dy[v] == -1){
dy[v] = dx[u]+1;
if(y[v] == -1) dis = dy[v];  //如果已经可以匹配就不用增广下面的点先用了再说
else{
dx[y[v]] = dy[v]+1;    //如果已经匹配看下还能不能增广
q.push(y[v]);
}
}
}
}
return dis != inf; //判断是否有点可以增广如果不能就是inf
}
bool find(int u){
for(int v = 0; v < m; v++)
if(!vis[v]&&g[u][v]&&dy[v]==dx[u]+1){   //如果这个v是被u第一次就发现的
vis[v] = 1;
if(y[v]!=-1    &&dy[v] == dis)continue; //如果v已经被匹配并且这个v对应路径已经没办法增广了
if(y[v] == -1||find(y[v])){
x[u] = v;
y[v] = u;
return true;
}
}
return false;
}
int MaxMatch(){
int ans = 0;
memset(x,-1,sizeof(x));
memset(y,-1,sizeof(y));
while(search()){
memset(vis,0,sizeof(vis));
for(int i = 0; i < n; i++)
if(x[i] == -1&&find(i)) ans++;
}
return ans;
}
double gettime(pos a,pos b){
return sqrt(pow(a.x-b.x,2)+pow(a.y-b.y,2))/a.s;
}
void init(){
memset(g,0,sizeof(g));
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++){
double t = gettime(a[i],b[j]);
//    printf("%lf %lf\n",t,T);
if(t<=T){
g[i][j] = 1;
//cout<<"1"<<endl;
}
}
}
int main(){
int t;
scanf("%d",&t);
for(int casei = 1; casei <= t; casei++){
scanf("%lf",&T);
scanf("%d",&n);
for(int i = 0; i < n; i++)
scanf("%lf%lf%lf",&a[i].x,&a[i].y,&a[i].s);
scanf("%d",&m);
for(int i = 0; i < m; i++)
scanf("%lf%lf",&b[i].x,&b[i].y);
init();
printf("Scenario #%d:\n",casei);
printf("%d\n\n",MaxMatch());
}
return 0;
}