标签：des style blog class code java
2 4312 12.4 .... ...1 3 5...9.31. 71.8...9. 32...6... ........3 .8.5.3... 4....1.5. 8..9...4. ...1..9.. .....7... 4 ...86.....D.A... .A.C.G.49....65E .......3B61C..DG 3...89.D7....24. ....4..G.9F2BD.. 49...C5.....7... 1.C..8.B6....... .6A.2.D...4.89.5 8F3BG.E24.A...7. ...6.3.A.1...... D.........5.1E2. .G...D.9........ ......F6.7.....3 6D.9.7..EG...B.. 51B.A..8........ ........F.C..71.
Not Minimal Multiple Solutions 9BG86F253ED4A1C7 7ADC1GB4928F365E F245EA73B61C98DG 3E6189CD7AG5F24B E873461G59F2BDAC 492D3C5FA8EB7G61 15CF98AB6D7G43E2 B6AG2ED7C34189F5 8F3BG1E24CAD6579 C756F38A219EG4BD D49A7B6CGF531E28 2G1E5D498B67CF3A GCE4D5F617B82A93 6DF9C731EG2A5B84 51B7A298D436ECGF A382B4GEF5C9D716
先判断是否有解，无解或者多解直接返回，唯一解的话判断是否为最小解，加入是最小解的话输出最小解。
判断前面的部分只需要dfs跑一次，假如解数为0，无解，解数大于1，多解，判断是否为最小解需要枚举把给定的矩阵里面的字母换成‘.‘,然后dlx判定
是否为多解，假如存在不是多解的情况，直接break，说明不是最小解，否则输出
代码：
/* ***********************************************
Author :_rabbit
Created Time :2014/5/1 18:36:44
File Name :12.cpp
************************************************ */
#pragma comment(linker, "/STACK:102400000,102400000")
#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <sstream>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <string>
#include <time.h>
#include <math.h>
#include <queue>
#include <stack>
#include <set>
#include <map>
using namespace std;
#define INF 0x3f3f3f3f
#define eps 1e-8
#define pi acos(-1.0)
typedef long long ll;
int tmp[100100];
int change1(char ch){
if(ch>=‘0‘&&ch<=‘9‘)return ch-‘0‘;
else return 10+ch-‘A‘;
}
char change2(int x){
if(x>=0&&x<=9)return x+‘0‘;
return (x-10)+‘A‘;
}
struct DLX{
const static int maxn=2001000;
#define FF(i,A,s) for(int i = A[s];i != s;i = A[i])
int L[maxn],R[maxn],U[maxn],D[maxn];
int size,col[maxn],row[maxn],s[maxn],H[maxn];
bool vis[10000];
int ans[maxn],cnt,tot;
void init(int m){
for(int i=0;i<=m;i++){
L[i]=i-1;R[i]=i+1;U[i]=D[i]=i;s[i]=0;
}
memset(H,-1,sizeof(H));
L[0]=m;R[m]=0;size=m+1;
tot=0;
}
void link(int r,int c){
U[size]=c;D[size]=D[c];U[D[c]]=size;D[c]=size;
if(H[r]<0)H[r]=L[size]=R[size]=size;
else {
L[size]=H[r];R[size]=R[H[r]];
L[R[H[r]]]=size;R[H[r]]=size;
}
s[c]++;col[size]=c;row[size]=r;size++;
}
void del(int c){//精确覆盖
L[R[c]]=L[c];R[L[c]]=R[c];
FF(i,D,c)FF(j,R,i)U[D[j]]=U[j],D[U[j]]=D[j],--s[col[j]];
}
void add(int c){ //精确覆盖
R[L[c]]=L[R[c]]=c;
FF(i,U,c)FF(j,L,i)++s[col[U[D[j]]=D[U[j]]=j]];
}
int dfs(int k){//精确覆盖
if(!R[0]&&k){
memcpy(ans,tmp,sizeof(tmp));cnt=k;
return ++tot;
}
int c=R[0];FF(i,R,0)if(s[c]>s[i])c=i;
del(c);
FF(i,D,c){
FF(j,R,i)del(col[j]);
tmp[k]=row[i];
if(dfs(k+1)==2)return 2;
FF(j,L,i)add(col[j]);
}
add(c);
return 0;
}
void remove(int c){//重复覆盖
FF(i,D,c)L[R[i]]=L[i],R[L[i]]=R[i];
}
void resume(int c){//重复覆盖
FF(i,U,c)L[R[i]]=R[L[i]]=i;
}
int A(){//估价函数
int res=0;
memset(vis,0,sizeof(vis));
FF(i,R,0)if(!vis[i]){
res++;vis[i]=1;
FF(j,D,i)FF(k,R,j)vis[col[k]]=1;
}
return res;
}
void dfs(int now,int &ans){//重复覆盖
if(R[0]==0)ans=min(ans,now);
else if(now+A()<ans){
int temp=INF,c;
FF(i,R,0)if(temp>s[i])temp=s[i],c=i;
FF(i,D,c){
remove(i);FF(j,R,i)remove(j);
dfs(now+1,ans);
FF(j,L,i)resume(j);resume(i);
}
}
}
}dlx;
const int SLOT=0;
const int ROW=1;
const int COL=2;
const int SUB=3;
int encode(int a,int b,int c,int n){
if(n==2)return 16*a+4*b+c+1;
if(n==3)return 81*a+9*b+c+1;
if(n==4)return 256*a+16*b+c+1;
}
void decode(int code,int &a,int &b,int &c,int n){
code--;int pp=n*n;
c=code%pp;code/=pp;
b=code%pp;code/=pp;
a=code;
}
char str[20][20];
int build(int n){
dlx.init(4*n*n*n*n);
for(int r=0;r<n*n;r++)
for(int c=0;c<=n*n;c++)
for(int k=1;k<=n*n;k++)
if(str[r][c]==‘.‘||str[r][c]==change2(k)){
int p=encode(r,c,k-1,n);
int a1,a2,a3,a4;
dlx.link(p,a1=encode(SLOT,r,c,n));
dlx.link(p,a2=encode(ROW,r,k-1,n));
dlx.link(p,a3=encode(COL,c,k-1,n));
dlx.link(p,a4=encode(SUB,(r/n)*n+c/n,k-1,n));
// cout<<"han: "<<p<<" "<<a1<<" "<<a2<<" "<<a3<<" "<<a4<<endl;
}
return dlx.dfs(0);
}
int main()
{
//freopen("data.in","r",stdin);
//freopen("data.out","w",stdout);
int n;
while(~scanf("%d",&n)){
for(int i=0;i<n*n;i++)scanf("%s",str[i]);
int hh=build(n);
//cout<<"hh="<<hh<<" "<<dlx.tot<<" "<<dlx.cnt<<endl;
if(dlx.tot==0)puts("No Solution");
else if(dlx.tot==2)puts("Multiple Solutions");
else{
int flag=1;
for(int i=0;i<n*n;i++)
for(int j=0;j<n*n;j++){
if(str[i][j]==‘.‘)continue;
char ch=str[i][j];str[i][j]=‘.‘;
build(n);
if(dlx.tot!=2){
flag=0;
break;
}
str[i][j]=ch;
}
if(!flag)puts("Not Minimal");
else {
build(n);
for(int i=0;i<dlx.cnt;i++){
int r,c,v;
decode(dlx.ans[i],r,c,v,n);
str[r][c]=change2(v+1);
}
for(int i=0;i<n*n;i++)printf("%s\n",str[i]);
}
}
}
return 0;
}
标签：des style blog class code java
原文地址：http://blog.csdn.net/xianxingwuguan1/article/details/24849931
