[DLX precise coverage] HDU 1603 A puzzling problem

Source: Internet
Author: User

Test instructions

Give you n pieces of debris that cannot be rotated or folded.

Ask if you can use some of these pieces to spell out 4*4 squares.


Cover the naked question exactly.

The map is to see where each fragment can be placed in the 4*4, as a row.

The column is 4*4=16, plus n fragments, which is 16+n.

and pay attention to the established decision.


#include "stdio.h" #include "algorithm" #include "string.h" #include "iostream" #include "queue" #include "map" #include "    Vector "#include" string "using namespace std; #define N 1005*1005#define RN 1005#define M 1005struct dlx{int n,m,c;    int u[n],d[n],l[n],r[n],row[n],col[n];    int h[m],s[m],cnt,ans[m];        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==0?m:i-1);            R[i]= (i==m?0:i+1);        s[i]=0;        } c=m;    for (int i=1; i<=n; i++) h[i]=-1;        } void link (int x,int y) {C + +;        Row[c]=x;        Col[c]=y;        s[y]++;        U[c]=u[y];        D[c]=y;        D[u[y]]=c;        U[y]=c;        if (h[x]==-1) h[x]=l[c]=r[c]=c;            else {l[c]=l[h[x]];            R[C]=H[X];            R[l[h[x]]]=c;        L[h[x]]=c;        }} void del (int x) {r[l[x]]=r[x];        L[R[X]]=L[X];  for (int i=d[x]; i!=x; 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 rec (int x) {for (int. i=u[x]; i!=x; 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[x]]=x;    L[r[x]]=x; } int Dance (int x) {if (r[0]==0 | |            R[0]&GT;16) {cnt=x;        return 1;        } int now=r[0];        for (int i=r[0]; i!=0 && i<=16; i=r[i]) {if (S[i]<s[now]) now=i;        } del (now);            for (int i=d[now]; i!=now; I=d[i]) {ans[x]=row[i];            for (int j=r[i]; j!=i; J=r[j] del (col[j]);            if (dance (x+1)) return 1;        for (int j=l[i]; j!=i; j=l[j]) rec (col[j]);        } rec (now);    return 0; }} dlx;struct node{intM,id; int w[44];}    Kx[1234];int Main () {int n;        while (scanf ("%d", &n), n) {int cnt=0;        Dlx.init (N*16,16+n);            for (int i=1; i<=n; i++) {int A, B;            scanf ("%d%d", &a,&b);            Char v[12][12];            for (int j=0; j<a; j + +) scanf ("%s", V[j]);                    for (int xx=1, xx+a<=5; xx++) {for (int yy=1; yy+b<=5; yy++) {                    cnt++;                    kx[cnt].m=0;                    Kx[cnt].id=i;                            for (int x=0; x<a; x + +) {for (int y=0; y<b; y++) { if (v[x][y]== ' 1 ') {int tep= (xx+x-1) *4+                                (Yy+y);                                Dlx.link (Cnt,tep);                            Kx[cnt].w[kx[cnt].m++]=tep;                }                        }                    }    Dlx.link (Cnt,16+i);        }}} int f=dlx.dance (0);        if (f==0) puts ("No solution possible");            else {char mp[10][10];                    for (int i=0;i<dlx.cnt;i++) {for (int j=0;j<kx[dlx.ans[i]].m;j++) {                    int x, y;                    x= (kx[dlx.ans[i]].w[j]-1)/4;                    Y=kx[dlx.ans[i]].w[j]%4-1;                    if (y==-1) y=3;                mp[x][y]=kx[dlx.ans[i]].id+ ' 0 ';                }} for (int i=0;i<4;i++) {mp[i][4]= ');            Puts (Mp[i]);    }} puts (""); } return 0;}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

[DLX precise coverage] HDU 1603 A puzzling problem

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.