FZU 1686 神龙的难题（重复覆盖）

重复覆盖模板题。
但是一开始T的不要不要的，迫不得已，改了自己的模板。。。

//
//  Created by  CQU_CST_WuErli
//  Copyright (c) 2016 CQU_CST_WuErli. All rights reserved.
//
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <queue>
#include <stack>
#include <set>
#include <algorithm>
#include <sstream>
#include <ctime>
#include <assert.h>

const int MAX_L=2005;// For BigInteger
const int INF_INT=0x3f3f3f3f;
const long long INF_LL=0x7fffffff;
const int MOD=1e9+7;
const double eps=1e-9;
const double pi=acos(-1);
typedef long long  ll;
using namespace std;

const int maxm = 15*15+10;
const int maxn = 15*15+10;
const int maxnode = maxn*maxm;
struct DLX {
int n,m;
int L[maxnode],R[maxnode],U[maxnode],D[maxnode];
int Row[maxnode],Col[maxnode];
int H[maxnode],S[maxnode];
int ans;    //  need update
int size;
void init(int _n,int _m) {
n=_n,m=_m;
for (int i=0;i<=m;i++) {
U[i]=D[i]=i;
L[i]=i-1;R[i]=i+1;
S[i]=0;
}
L[0]=m;R[m]=0;
for (int i=1;i<=n;i++) H[i]=-1;
size=m;
}
void link(int row,int col) {
++S[Col[++size]=col];
Row[size]=row;
D[size]=D[col];
U[D[col]]=size;
U[size]=col;
D[col]=size;
if(H[row]<0)H[row]=L[size]=R[size]=size;
else
{
R[size]=R[H[row]];
L[R[H[row]]]=size;
L[size]=H[row];
R[H[row]]=size;
}
}
// exact cover
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]) {
U[D[j]]=j;
D[U[j]]=j;
S[Col[j]]++;
}
}
R[L[c]]=c;
L[R[c]]=c;
}
bool dfs(int cnt) {
if (ans!=-1) return true;
if (R[0]==0) {
ans=cnt;
return true;
}
int c=R[0];
for (int i=R[0];i!=0;i=R[i]){
if (S[c]>S[i]) c=i;
}
remove(c);
for (int i=D[c];i!=c;i=D[i]) {
for (int j=R[i];j!=i;j=R[j]) {
remove(Col[j]);
}
if (dfs(cnt+1)) return true;
for (int j=L[i];j!=i;j=L[j]) {
resume(Col[j]);
}
}
resume(c);
return false;
}
// exact cover ends;
// multiple cover
void del(int c) {
for (int i=D[c];i!=c;i=D[i]) {
L[R[i]]=L[i];
R[L[i]]=R[i];
}
}
void rec(int c) {
for (int i=U[c];i!=c;i=U[i]) {
L[R[i]]=R[L[i]]=i;
}
}
int vis[maxn];
int h() {
int ret=0;
for(int c=R[0];c!=0;c=R[c]) vis[c]=true;
for(int c=R[0];c!=0;c=R[c]) if(vis[c]) {
ret++;
vis[c]=false;
for(int i=D[c];i!=c;i=D[i])
for(int j=R[i];j!=i;j=R[j])
vis[Col[j]]=false;
}
return ret;
}
void DFS(int cnt) {
if (cnt+h()>=ans) return;
if (R[0]==0) {
if (cnt<ans) ans=cnt;
return;
}
int c=R[0];
for (int i=R[0];i!=0;i=R[i])
if (S[c]>S[i]) c=i;
for (int i=D[c];i!=c;i=D[i]) {
del(i);
for (int j=R[i];j!=i;j=R[j]) del(j);
DFS(cnt+1);
for (int j=L[i];j!=i;j=L[j]) rec(j);
rec(i);
}
return;
}
// multiple cover ends;
}dlx;

int n,m;
int a[20][20];
int id[20][20];

int main() {
#ifdef LOCAL
freopen("C:\\Users\\john\\Desktop\\in.txt","r",stdin);
// freopen("C:\\Users\\john\\Desktop\\out.txt","w",stdout);
#endif
while(scanf("%d%d",&n,&m)==2) {
int cnt=0;memset(id,0,sizeof(id));
for (int i=1;i<=n;i++) for (int j=1;j<=m;j++) {
scanf("%d",&a[i][j]);
if (a[i][j]==1) id[i][j]=++cnt;
}
int n1,m1;
scanf("%d%d",&n1,&m1);
dlx.init(n*m,cnt);
int idx=0;
for (int i=1;i<=n;i++) for (int j=1;j<=m;j++) {
idx++;
for (int s=0;s<n1;s++) for (int t=0;t<m1;t++) if (i+s>=1 && i+s<=n && j+t>=1 && j+t<=m && id[i+s][j+t]) {
dlx.link(idx,id[i+s][j+t]);
}
}
dlx.ans=INF_INT;
dlx.DFS(0);
printf("%d\n",dlx.ans);
}
return 0;
}