#include #include #include #include using namespace std; const int maxn=1010,maxm=510; const int maxnode=maxn*maxm; const int INF=0x3f3f3f3f; int n,m; bool flag; struct DLX { int n,m,size; int U[maxnode],D[maxnode],R[maxnode],L[maxnode],Row[maxnode],Col[maxnode]; int H[maxn],S[maxm]; int ansd,ans[maxn]; int LAMP[maxn]; bool vis[maxn]; void init(int _n,int _m) { n=_n; m=_m; for(int i=0;i<=m;i++) { S[i]=0; U[i]=D[i]=i; L[i]=i-1; R[i]=i+1; } R[m]=0; L[0]=m; size=m; for(int i=1;i<=n;i++) { vis[i]=false; LAMP[i]=0; H[i]=-1; } flag=false; } void Link(int r,int c) { ++S[Col[++size]=c]; Row[size]=r; D[size]=D[c]; U[D[c]]=size; U[size]=c; D[c]=size; if(H[r]<0) H[r]=L[size]=R[size]=size; else { R[size]=R[H[r]]; L[R[H[r]]]=size; L[size]=H[r]; R[H[r]]=size; } } void remove(int c) { for(int i=D[c];i!=c;i=D[i]) L[R[i]]=L[i],R[L[i]]=R[i]; } void resume(int c) { for(int i=U[c];i!=c;i=U[i]) L[R[i]]=R[L[i]]=i; } void Dance(int d) { if(flag) return ; if(R[0]==0) { for(int i=0;i