Dancing Link基础题2
HUST 1017 精确覆盖
// whn6325689
// Mr.Phoebe
// http://blog.csdn.net/u013007900
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>
#include <functional>
#include <numeric>
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef complex<ld> point;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef vector<int> vi;
#define CLR(x,y) memset(x,y,sizeof(x))
#define mp(x,y) make_pair(x,y)
#define pb(x) push_back(x)
#define lowbit(x) (x&(-x))
#define MID(x,y) (x+((y-x)>>1))
#define eps 1e-9
#define PI acos(-1.0)
#define INF 0x3f3f3f3f
#define LLINF 1LL<<62
template<class T>
inline bool read(T &n)
{
T x = 0, tmp = 1; char c = getchar();
while((c < '0' || c > '9') && c != '-' && c != EOF) c = getchar();
if(c == EOF) return false;
if(c == '-') c = getchar(), tmp = -1;
while(c >= '0' && c <= '9') x *= 10, x += (c - '0'),c = getchar();
n = x*tmp;
return true;
}
template <class T>
inline void write(T n)
{
if(n < 0)
{
putchar('-');
n = -n;
}
int len = 0,data[20];
while(n)
{
data[len++] = n%10;
n /= 10;
}
if(!len) data[len++] = 0;
while(len--) putchar(data[len]+48);
}
//-----------------------------------
const int N = 1010;
const int MaxN = 1010;
const int MaxM = 1010;
const int maxnode = MaxN*MaxM + 10;
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];
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++)H[i] = -1;
}
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)
{
L[R[c]] = L[c]; R[L[c]] = R[c];
for(int i = D[c];i != c;i = D[i])
for(int j = R[i];j != i;j = R[j])
{
U[D[j]] = U[j];
D[U[j]] = D[j];
--S[Col[j]];
}
}
void resume(int c)
{
for(int i = U[c];i != c;i = U[i])
for(int j = L[i];j != i;j = L[j])
++S[Col[U[D[j]]=D[U[j]]=j]];
L[R[c]] = R[L[c]] = c;
}
bool Dance(int d)
{
if(R[0] == 0)
{
write(d),putchar(' ');
for(int i = 0;i < d; i++)
write(ans[i]),putchar(" \n"[i==d-1]);
return true;
}
int c = R[0];
for(int i = R[0];i != 0;i = R[i])
if(S[i] < S[c])
c = i;
remove(c);
for(int i = D[c];i != c;i = D[i])
{
ans[d] = Row[i];
for(int j = R[i];j != i;j = R[j])remove(Col[j]);
if(Dance(d+1)) return true;
for(int j = L[i];j != i;j = L[j])resume(Col[j]);
}
resume(c);
return false;
}
}dlx;
int main()
{
// freopen("data.txt","r",stdin);
int n,m;
while(read(n)&&read(m))
{
dlx.init(n,m);
for(int i=1,num,cc;i<=n;i++)
{
read(num);
for(int j=0;j<num;j++)
{
read(cc);
dlx.Link(i,cc);
}
}
if(dlx.Dance(0))
continue;
else
puts("NO");
}
return 0;
}
FZU 1686 重复覆盖
// whn6325689
// Mr.Phoebe
// http://blog.csdn.net/u013007900
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>
#include <functional>
#include <numeric>
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef complex<ld> point;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef vector<int> vi;
#define CLR(x,y) memset(x,y,sizeof(x))
#define mp(x,y) make_pair(x,y)
#define pb(x) push_back(x)
#define lowbit(x) (x&(-x))
#define MID(x,y) (x+((y-x)>>1))
#define speed std::ios::sync_with_stdio(false);
#define eps 1e-9
#define PI acos(-1.0)
#define INF 0x3f3f3f3f
#define LLINF 1LL<<62
template<class T>
inline bool read(T &n)
{
T x = 0, tmp = 1;
char c = getchar();
while((c < '0' || c > '9') && c != '-' && c != EOF) c = getchar();
if(c == EOF) return false;
if(c == '-') c = getchar(), tmp = -1;
while(c >= '0' && c <= '9') x *= 10, x += (c - '0'),c = getchar();
n = x*tmp;
return true;
}
template <class T>
inline void write(T n)
{
if(n < 0)
{
putchar('-');
n = -n;
}
int len = 0,data[20];
while(n)
{
data[len++] = n%10;
n /= 10;
}
if(!len) data[len++] = 0;
while(len--) putchar(data[len]+48);
}
//-----------------------------------
const int N=16;
const int maxn=N*N;
const int maxm=N*N;
const int maxnode=maxn*maxm+10;
int n,m,n1,m1;
int ma[N][N];
struct DLX
{
int n,m,size;
int U[maxnode],D[maxnode],R[maxnode],L[maxnode],Row[maxnode],Col[maxnode];
int H[maxn],S[maxn];
int ansd,ans[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++)
H[i]=-1;
}
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;
}
bool v[maxnode];
int h()
{
int ret=0;
for(int c=R[0];c!=0;c=R[c])
v[c]=true;
for(int c=R[0];c!=0;c=R[c])
if(v[c])
{
ret++;
v[c]=false;
for(int i=D[c];i!=c;i=D[i])
for(int j=R[i];j!=i;j=R[j])
v[Col[j]]=false;
}
return ret;
}
void dance(int d)
{
if(d+h()>=ansd)
return ;
if(R[0]==0)
{
if(ansd>d)
ansd=d;
return ;
}
int c=R[0];
for(int i=R[0];i!=0;i=R[i])
if(S[i]<S[c])
c=i;
for(int i=D[c];i!=c;i=D[i])
{
remove(i);
for(int j=R[i];j!=i;j=R[j])
remove(j);
dance(d+1);
for(int j=L[i];j!=i;j=L[j])
resume(j);
resume(i);
}
}
}x;
int main()
{
freopen("data.txt","r",stdin);
while(read(n)&&read(m))
{
int size=0;
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++)
{
read(ma[i][j]);
if(ma[i][j])
ma[i][j]=(++size);
}
read(n1),read(m1);
x.init((n-n1+1)*(m-m1+1),size);
size=1;
for(int i=1;i<=n-n1+1;i++)
for(int j=1;j<=m-m1+1;j++)
{
for(int ii=0;ii<n1&&i+ii<=n;ii++)
for(int jj=0;jj<m1&&j+jj<=m;jj++)
if(ma[i+ii][j+jj])
x.link(size,ma[i+ii][j+jj]);
size++;
}
x.ansd=INF;
x.dance(0);
printf("%d\n",x.ansd);
}
return 0;
}
注意怎么抽象出行和列