Files
OI-source/2.1309.cpp
2023-08-03 09:22:52 +08:00

123 lines
2.5 KiB
C++

#include<cstdio>
#include<cstring>
#include<vector>
#include<cassert>
using namespace std;
const int maxn=2010;
const int maxnode=20000;
struct DLX
{
int n,sz;
int s[maxn];
int row[maxnode],col[maxnode];
int U[maxnode],D[maxnode],L[maxnode],R[maxnode];
int ansd,ans[300];
void init(int n)
{
this->n=n; sz=n+1;
memset(s,0,sizeof(s));
for(int i=0;i<=n;i++) { U[i]=i; D[i]=i; L[i]=i-1; R[i]=i+1; }
L[0]=n; R[n]=0;
}
inline void push_back(int r,const vector<int> &cols)
{
int first=sz,szc=cols.size();
for(int i=0;i<szc;i++)
{
int c=cols[i];
L[sz]=sz-1; R[sz]=sz+1; D[sz]=c; U[sz]=U[c];
D[U[sz]]=sz; U[c]=sz;
row[sz]=r; col[sz]=c;
++s[c]; ++sz;
}
R[sz-1]=first; L[first]=sz-1;
}
#define For(i,A,s) for(int i=A[s];i!=s;i=A[i])
inline void remove(int c)
{
L[R[c]]=L[c]; R[L[c]]=R[c];
For(i,D,c) For(j,R,i) { U[D[j]]=U[j]; D[U[j]]=D[j]; --s[col[j]]; }
}
inline void restore(int c)
{
For(i,U,c) For(j,L,i) { ++s[col[j]]; U[D[j]]=j; D[U[j]]=j; }
L[R[c]]=c; R[L[c]]=c;
}
bool dfs(int d)
{
if(R[0]==0) { ansd=d; return true; }
int c=R[0];
For(i,R,0) if(s[i]<s[c]) c=i;
remove(c);
For(i,D,c)
{
ans[d]=row[i];
For(j,R,i) remove(col[j]);
if(dfs(d+1)) return true;
For(j,L,i) restore(col[j]);
}
restore(c);
return false;
}
bool solve(vector<int> &res)
{
res.clear();
if(!dfs(0)) return false;
for(int i=0;i<ansd;i++) res.push_back(ans[i]);
return true;
}
};
DLX solver;
const int Slot=0;
const int Row=1;
const int Col=2;
const int Sub=3;
inline int encode(int a,int b,int c) { return a*256+b*16+c+1; }
inline void decode(int code,int &a,int &b,int &c)
{
code--;
c=code%16;code/=16;
b=code%16;code/=16;
a=code;
}
char mp[16][20];
bool read()
{
for(int i=0;i<16;i++) if(scanf("%s",mp[i])!=1) return false;
return true;
}
int main()
{
#ifdef local
freopen("pro.in","r",stdin);
#endif
int kase=0;
while(read())
{
if(++kase!=1) printf("\n");
solver.init(1024);
for(int r=0;r<16;r++)
for(int c=0;c<16;c++)
for(int v=0;v<16;v++)
if(mp[r][c]=='-'||mp[r][c]=='A'+v)
{
vector<int> cols;
cols.push_back(encode(Slot,r,c));
cols.push_back(encode(Row,r,v));
cols.push_back(encode(Col,c,v));
cols.push_back(encode(Sub,(r/4)*4+c/4,v));
solver.push_back(encode(r,c,v),cols);
}
vector<int> ans;
solver.solve(ans);
for(int i=0;i<ans.size();i++)
{
int r,c,v;
decode(ans[i],r,c,v);
mp[r][c]='A'+v;
}
for(int i=0;i<16;i++) printf("%s\n",mp[i]);
}
return 0;
}