2013 Shandong Province Rubik ' s cube-cube BFS

Source: Internet
Author: User

Second-order Rubik's Cube, only 0, 1

Ask at least how many steps can be turned to each face is 0, or 1

BFS can, corresponding to a good rotation time of the relationship, because clockwise turn three times and counterclockwise Turn 1 times the same effect, so as long as 6 kinds of rotation can be, sentenced to use map save space, or directly to the time


#include "stdio.h" #include "string.h" #include "map" #include "queue" using namespace Std;bool mp[17000000];struct node{I NT X[24],t;};    int A[25];int gethash (node cur) {int cnt,i;    cnt=0;    for (i=0;i<24;i++) cnt=cnt*2+cur.x[i]; return CNT;}    int judge (node cur) {int i;    for (i=0;i<24;i+=4) if (cur.x[i]!=cur.x[i+1] | | cur.x[i]!=cur.x[i+2] | | cur.x[i]!=cur.x[i+3]) return-1; return 1;}    int BFs () {queue<node>q;    Node Cur,next;    int sum,i,temp;    sum=0;        for (i=0;i<24;i++) {cur.x[i]=a[i];    Sum+=a[i];    } if (sum%4!=0) return-1;    cur.t=0;    if (judge (cur) ==1) return 0;    Q.push (cur);    Memset (Mp,false,sizeof (MP));    Mp[gethash (cur)]=true;        while (!q.empty ()) {Cur=q.front ();        Q.pop (); Next=cur;  Zheng Shun temp=next.x[0];  NEXT.X[0]=NEXT.X[2];  NEXT.X[2]=NEXT.X[3];  NEXT.X[3]=NEXT.X[1];        Next.x[1]=temp;  TEMP=NEXT.X[9]; NEXT.X[9]=NEXT.X[15]; Next.x[15]=next.x[17];next.x[17]=next. x[4];        Next.x[4]=temp;  TEMP=NEXT.X[8]; NEXT.X[8]=NEXT.X[13]; NEXT.X[13]=NEXT.X[16];NEXT.X[16]=NEXT.X[6];        Next.x[6]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); } next=cur;  positive inverse temp=next.x[0];  NEXT.X[0]=NEXT.X[1];  NEXT.X[1]=NEXT.X[3];  NEXT.X[3]=NEXT.X[2];        Next.x[2]=temp;  TEMP=NEXT.X[9];  NEXT.X[9]=NEXT.X[4]; NEXT.X[4]=NEXT.X[17];        Next.x[17]=next.x[15];next.x[15]=temp;  TEMP=NEXT.X[8];  NEXT.X[8]=NEXT.X[6]; NEXT.X[6]=NEXT.X[16];        Next.x[16]=next.x[13];next.x[13]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); } next=cur;  Right Shun temp=next.x[4];  NEXT.X[4]=NEXT.X[6];  NEXT.X[6]=NEXT.X[7];  NEXT.X[7]=NEXT.X[5];        Next.x[5]=temp; Temp=next. X[8];  NEXT.X[8]=NEXT.X[3]; NEXT.X[3]=NEXT.X[19];        Next.x[19]=next.x[20];next.x[20]=temp; TEMP=NEXT.X[10]; NEXT.X[10]=NEXT.X[1]; NEXT.X[1]=NEXT.X[17];        Next.x[17]=next.x[22];next.x[22]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); } next=cur;  Right inverse temp=next.x[4];  NEXT.X[4]=NEXT.X[5];  NEXT.X[5]=NEXT.X[7];  NEXT.X[7]=NEXT.X[6];        Next.x[6]=temp;  TEMP=NEXT.X[8]; NEXT.X[8]=NEXT.X[20]; NEXT.X[20]=NEXT.X[19];NEXT.X[19]=NEXT.X[3];        Next.x[3]=temp; TEMP=NEXT.X[10]; NEXT.X[10]=NEXT.X[22];NEXT.X[22]=NEXT.X[17];NEXT.X[17]=NEXT.X[1];        Next.x[1]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); } next=cur; Shang Shun temp=next.x[11]; NEXT.X[11]=NEXT.X[9]; NEXT.X[9]=NEXT.X[8]; NEXT.X[8]=NEXT.X[10];        Next.x[10]=temp;  TEMP=NEXT.X[0];  NEXT.X[0]=NEXT.X[4]; NEXT.X[4]=NEXT.X[20];        Next.x[20]=next.x[12];next.x[12]=temp;  TEMP=NEXT.X[1];  NEXT.X[1]=NEXT.X[5]; NEXT.X[5]=NEXT.X[21];        Next.x[21]=next.x[13];next.x[13]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); } next=cur; Upper Inverse temp=next.x[11]; NEXT.X[11]=NEXT.X[10];NEXT.X[10]=NEXT.X[8];  NEXT.X[8]=NEXT.X[9];        Next.x[9]=temp;  TEMP=NEXT.X[0]; NEXT.X[0]=NEXT.X[12]; NEXT.X[12]=NEXT.X[20];NEXT.X[20]=NEXT.X[4];        Next.x[4]=temp;  TEMP=NEXT.X[1]; NEXT.X[1]=NEXT.X[13]; NEXT.X[13]=NEXT.X[21];NEXT.X[21]=NEXT.X[5];        Next.x[5]=temp;        Temp=gethash (next);            if (mp[temp]==false) {mp[temp]=true;            next.t++;            if (judge (next) ==1) return next.t;        Q.push (next); }} RETurn-1;}    int main () {int n,i,ans;    scanf ("%d", &n);        while (n--) {for (i=0;i<24;i++) scanf ("%d", &a[i]);        Ans=bfs ();        if (ans==-1) printf ("impossible!\n");    else printf ("%d\n", ans); } return 0;}


2013 Shandong Province Rubik ' s cube-cube BFS

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.