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水能流过的地方,光就能穿过。
逝者如流水,光阴如梭
所以光线可以不用管,就是前面和后面联通就行,把所有相连的图形连inf的边,每个点拆成两个点,中间连1,最小割即为花费。
(这个计算几何良心)
AC Code:
#include<bits/stdc++.h>
#define maxn 705
#define maxm maxn * maxn * 4
#define eps 1e-7
#define inf 1e8
using namespace std;
int x,y,n;
int typ[maxn],x1[maxn],y3[maxn],x2[maxn],y2[maxn],r[maxn];
double sqr(int a){ return 1.0*a*a; }
double dist(int a,int b,int c,int d){ return sqrt(sqr(a-c)+sqr(b-d)); }
bool check1(int a,int b)
{
return sqrt(sqr(x1[a]-x1[b])+sqr(y3[a]-y3[b]))<=r[a]+r[b]+eps;
}
bool check2(int a,int b)
{
if(x1[a]>=x1[b] && x1[a]<=x2[b] && y3[a]>=y3[b] && y3[a]<=y2[b]) return 1;
if((y3[b]<=y3[a]&&y3[a]<=y2[b] && min(abs(x1[a]-x1[b]),abs(x1[a]-x2[b]))<=r[a]) ||
(x1[b]<=x1[a]&&x1[a]<=x2[b] && min(abs(y3[a]-y3[b]),abs(y3[a]-y2[b]))<=r[a]))
return 1;
if(dist(x1[a],y3[a],x1[b],y3[b]) <= r[a] + eps) return 1;
if(dist(x1[a],y3[a],x1[b],y2[b]) <= r[a] + eps) return 1;
if(dist(x1[a],y3[a],x2[b],y3[b]) <= r[a] + eps) return 1;
if(dist(x1[a],y3[a],x2[b],y2[b]) <= r[a] + eps) return 1;
return 0;
}
bool check3(int a,int b)
{
if(x2[a] < x1[b] || x2[b] < x1[a]) return 0;
if(y2[a] < y3[b] || y2[b] < y3[a]) return 0;
return 1;
}
int h[maxn],gap[maxn],S,T;
int info[maxn],Prev[maxm],to[maxm],cap[maxm],cnt_e=1;
void Node(int u,int v,int c){ Prev[++cnt_e]=info[u],info[u]=cnt_e,to[cnt_e]=v,cap[cnt_e]=c; }
void Line(int u,int v,int c,int d=0){ Node(u,v,c),Node(v,u,d); }
int aug(int now,int Max)
{ if(now == T) return Max;
int inc , st = Max;
for(int i=info[now];i;i=Prev[i])
if(cap[i] && h[to[i]] + 1 == h[now])
{
inc = aug(to[i] , min(cap[i],st));
st-=inc,cap[i]-=inc,cap[i^1]+=inc;
if(!st || h[S] > T) return Max - st;
}
if(!--gap[h[now]]) h[S]=T+1;
++gap[++h[now]];
return Max - st;
}
int main()
{
scanf("%d%d%d",&x,&y,&n);
S = 2 * n + 1 ,T = 2 * n + 2;
for(int i=1;i<=n;i++)
{ scanf("%d",&typ[i]);
Line(i,i+n,1);
if(typ[i] == 1)
{
scanf("%d%d%d",&x1[i],&y3[i],&r[i]);
if(x1[i]<=x)
{
if(y3[i]<=r[i]) Line(S,i,inf);
if(y3[i]+r[i]>=y) Line(i+n,T,inf);
}
else
{
if(dist(x1[i],y3[i],x,y)<=r[i]+eps) Line(i+n,T,inf);
if(dist(x1[i],y3[i],x,0)<=r[i]+eps) Line(S,i,inf);
}
}
else
{
scanf("%d%d%d%d",&x1[i],&y3[i],&x2[i],&y2[i]);
if(x1[i]<=x)
{
if(y3[i]<=0) Line(S,i,inf);
if(y2[i]>=y) Line(i+n,T,inf);
}
}
}
for(int i=1;i<=n;i++)
for(int j=i+1;j<=n;j++)
{
if(typ[i]==1&&typ[j]==1&&check1(i,j)) Line(i+n,j,inf),Line(j+n,i,inf);
if(typ[i]==1&&typ[j]==2&&check2(i,j)) Line(i+n,j,inf),Line(j+n,i,inf);
if(typ[i]==2&&typ[j]==1&&check2(j,i)) Line(i+n,j,inf),Line(j+n,i,inf);
if(typ[i]==2&&typ[j]==2&&check3(i,j)) Line(i+n,j,inf),Line(j+n,i,inf);
}
int stm = 0;
for(gap[0]=T;h[S]<=T;)
stm+=aug(S,inf);
printf("%d\n",stm);
}