hdu 2389 Rain on your Parade （二分匹配 Hc 算法）

#include<iostream>
#include<cstring>
#include<string>
#include<cstdio>
#include<stdio.h>
#include<algorithm>
#include<cmath>
#include<set>
#include<map>
#include<queue>
#include<vector>
using namespace std;

#define inf 0x3f3f3f3f
#define eps 1e-9
#define mod 1000000007
#define FOR(i,s,t) for(int i = s; i < t; ++i )
#define REP(i,s,t) for( int i = s; i <= t; ++i )
#define LL long long
#define ULL unsigned long long
#define pii pair<int,int>
#define MP make_pair
#define lson id << 1 , l , m
#define rson id << 1 | 1 , m + 1 , r
#define maxn ( 3000+10 )
#define maxe ( 50000+10 )


struct node {
int x, y;
int dis ( node ot ) {
return ( x - ot.x ) * ( x - ot.x ) + ( y - ot.y ) * ( y - ot.y );
}
}g[maxn], u[maxn];

int sp[maxn];
int G[maxn][maxn];

int mx[maxn], my[maxn], dx[maxn], dy[maxn];
int dis, nx, ny;
int Q[maxn*2];
bool vis[maxn];

bool search() {
memset( dx, -1, sizeof( dx ) );
memset( dy, -1, sizeof( dy ) );
dis = inf;
int head = 0, tail = 0;
for( int i = 0; i < nx; ++i ) {
if( mx[i] == -1 ) Q[tail ++] = i, dx[i] = 0;
}
while( head < tail ) {
int u = Q[head++];
if( dx[u] > dis ) break;
for( int v = 0; v < ny; ++v ) if( G[u][v] && dy[v] == -1 ) {
dy[v] = dx[u] + 1;
if( my[v] == -1 ) dis = dy[v];
else {
dx[my[v]] = dy[v] + 1;
Q[tail++] = my[v];
}
}
}
return dis != inf;
}

bool dfs ( int u ) {
for( int i = 0; i < ny; ++i ) if( G[u][i] && !vis[i] && dy[i] == dx[u] + 1 ) {
vis[i] =1;
if( my[i] != -1 && dis == dy[i] ) continue;
if( my[i] == -1 || dfs( my[i] ) ) {
my[i] = u;
mx[u] = i;
return 1;
}
}
return 0;
}

int match() {
int res = 0;
memset( mx, -1, sizeof( mx) );
memset( my, -1, sizeof( my ) );
while( search() ) {
memset( vis, 0, sizeof( vis ) );
for( int i= 0; i < nx; ++i )
if( mx[i] == -1 && dfs( i ) ) ++res;
}
return res;
}
int main () {
int T;
scanf("%d", &T );
int cas = 1;
for( cas = 1; cas <= T; ++cas ) {
int n, m, t;
scanf("%d%d", &t, &m ) ;
for( int i = 0; i < m; ++i ) {
scanf("%d%d%d", &g[i].x, &g[i].y, &sp[i] );
}
scanf("%d", &n );
for( int i = 0; i < n; ++i ) {
scanf("%d%d", &u[i].x, &u[i].y );
}
memset( G, 0, sizeof( G ) );
for( int i = 0; i < m; ++i ) {
for( int j = 0; j < n; ++j ) {
if( g[i].dis( u[j] ) <= ( sp[i] * t ) * ( sp[i] * t ) )
G[i][j] = 1;
}
}
nx = m, ny = n;
printf("Scenario #%d:\n", cas );
printf("%d\n\n", match() );
}
}