bzoj3820 虫逢

 1 #include <bits/stdc++.h>
 2 #define il inline
 3 #define RG register
 4 #define ll long long
 5 #define rhl (2573287)
 6 #define M (5000010)
 7 #define N (40010)
 8 
 9 using namespace std;
10 
11 struct edge{ int nt,to; }g[M];
12 struct data{ int x,y,z; }q[N];
13 
14 int a[N][135],mt[N],q1[M],q2[M],vis[M],head[rhl],n,m,l,num,cnt,res,flg;
15 char ch;
16 
17 il int cmp(const data &a,const data &b){
18   if (a.x==b.x) return a.y<b.y; return a.x<b.x;
19 }
20 
21 il int insert(RG int to){
22   RG int from=to%rhl;
23   for (RG int i=head[from];i;i=g[i].nt) if (g[i].to==to) return i;
24   g[++num]=(edge){head[from],to},head[from]=num; return num;
25 }
26 
27 il int eql(RG int x,RG int y){
28   ++flg; RG int mch=0;
29   for (RG int i=1;i<=l;++i) vis[a[x][i]]=flg;
30   for (RG int i=1;i<=l;++i) mch+=vis[a[y][i]]==flg;
31   return mch==(l>>1);
32 }
33 
34 il int solve(){
35   random_shuffle(q1+1,q1+num+1),random_shuffle(q2+1,q2+num+1),cnt=0; RG int mch=0;
36   for (RG int i=1;i<=n;++i){
37     if (mt[i]) continue; ++cnt,q[cnt].x=q1[a[i][1]],q[cnt].y=q2[a[i][1]],q[cnt].z=i;
38     for (RG int j=2;j<=l;++j) q[cnt].x=min(q[cnt].x,q1[a[i][j]]),q[cnt].y=min(q[cnt].y,q2[a[i][j]]);
39   }
40   sort(q+1,q+cnt+1,cmp);
41   for (RG int i=1,j;i<cnt;++i){
42     if (mt[q[i].z]) continue;
43     for (j=i;j<cnt && q[j+1].x==q[j].x && q[j+1].y==q[j].y;++j);
44     for (RG int u=i;u<j;++u){
45       if (mt[q[u].z]) continue;
46       for (RG int v=u+1;v<=j;++v)
47     if (!mt[q[v].z] && eql(q[u].z,q[v].z)){
48       mt[q[u].z]=q[v].z,mt[q[v].z]=q[u].z,++mch; break;
49     }
50     }
51   }
52   return mch;
53 }
54 
55 int main(){
56 #ifndef ONLINE_JUDGE
57   freopen("pairing.in","r",stdin);
58   freopen("pairing.out","w",stdout);
59 #endif
60   srand(19260817),cin>>n>>m>>l,n<<=1; while (ch<‘!‘) ch=getchar();
61   for (RG int i=1;i<=n;++i)
62     for (RG int j=1,x=0;j<=l;++j,x=0){
63       for (RG int k=1;k<=4;++k,ch=getchar()) x=(x<<7)+(int)ch;
64       a[i][j]=insert(x);
65     }
66   for (RG int i=1;i<=num;++i) q1[i]=q2[i]=i;
67   res=n>>1; while (res) res-=solve();
68   for (RG int i=1;i<=n;++i) printf("%d\n",mt[i]); return 0;
69 }