BFS爆搜

Dice

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)

Problem Description

There are 2 special dices on the table. On each face of the dice, a distinct number was written. Consider a₁.a₂,a₃,a₄,a₅,a₆ to be numbers written on top face, bottom face, left face, right face,
front face and back face of dice A. Similarly, consider b₁.b₂,b₃,b₄,b₅,b₆ to be numbers on specific faces of dice B. It’s guaranteed that all numbers written on dices are integers no smaller
than 1 and no more than 6 while a_i ≠ a_j and b_i ≠ b_j for all i ≠ j. Specially, sum of numbers on opposite faces may not be 7.

At the beginning, the two dices may face different(which means there exist some i, a_i ≠ b_i). Ddy wants to make the two dices look the same from all directions(which means for all i, a_i = b_i) only by the following
four rotation operations.(Please read the picture for more information)

Now Ddy wants to calculate the minimal steps that he has to take to achieve his goal.

Input

There are multiple test cases. Please process till EOF.

For each case, the first line consists of six integers a₁,a₂,a₃,a₄,a₅,a₆, representing the numbers on dice A.

The second line consists of six integers b₁,b₂,b₃,b₄,b₅,b₆, representing the numbers on dice B.

Output

For each test case, print a line with a number representing the answer. If there’s no way to make two dices exactly the same, output -1.

Sample Input

1 2 3 4 5 6
1 2 3 4 5 6
1 2 3 4 5 6
1 2 5 6 4 3
1 2 3 4 5 6
1 4 2 5 3 6

Sample Output

0
3
-1

Source

2014 ACM/ICPC Asia Regional Xi‘an Online

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <map>
#include <set>
#include <queue>

using namespace std;

struct DICE
{
	int face[6];
}A,B;

bool check(DICE a,DICE b)
{
	for(int i=0;i<6;i++)
		if(a.face[i]!=b.face[i]) return false;
	return true;
}

bool checkIMP(DICE x,DICE y)
{
	int a[6],b[6];
	for(int i=0;i<6;i++)
	{
		a[i]=x.face[i];
		b[i]=y.face[i];
	}
	sort(a,a+6);
	sort(b,b+6);
	for(int i=0;i<6;i++)
	{
		if(a[i]!=b[i]) return false;
	}
	return true;
}

void init(DICE& x)
{
	int a[6];
	for(int i=0;i<6;i++)
		a[i]=x.face[i];
	sort(a,a+6);
	for(int i=0;i<6;i++)
	{
		x.face[i]=lower_bound(a,a+6,x.face[i])-a+1;
	}
}

void showit(DICE x)
{
	for(int i=0;i<6;i++)
		cout<<x.face[i]<<",";
	cout<<endl;
}

int hash(DICE x)
{
	int ret=0;
	for(int i=0;i<6;i++)
		ret=ret*10+x.face[i];
	return ret;
}

void rhash(int h,DICE& x)
{
	for(int i=5;i>=0;i--)
	{
		x.face[i]=h%10;
		h/=10;
	}
}

void LEFT(DICE& X)
{
	int a[6];
	for(int i=0;i<6;i++)
		a[i]=X.face[i];
	X.face[0]=a[3];
	X.face[1]=a[2];
	X.face[2]=a[0];
	X.face[3]=a[1];
}

void RIGHT(DICE& X)
{
	int a[6];
	for(int i=0;i<6;i++)
		a[i]=X.face[i];
	X.face[0]=a[2];
	X.face[1]=a[3];
	X.face[3]=a[0];
	X.face[2]=a[1];
}

void UP(DICE& X)
{
	int a[6];
	for(int i=0;i<6;i++)
		a[i]=X.face[i];
	X.face[0]=a[5];
	X.face[1]=a[4];
	X.face[4]=a[0];
	X.face[5]=a[1];
}

void DOWN(DICE& X)
{
	int a[6];
	for(int i=0;i<6;i++)
		a[i]=X.face[i];
	X.face[0]=a[4];
	X.face[1]=a[5];
	X.face[4]=a[1];
	X.face[5]=a[0];
}

bool st[1000001];

void bfs()
{
	queue<int> q,qt;
	memset(st,0,sizeof(st));
	q.push(hash(A));
	st[hash(A)]=0;
	qt.push(0);
	bool flag=false;
	while(!q.empty())
	{
		int time=qt.front(); qt.pop();
		int zhi=q.front(); q.pop();

		DICE X,Y;int ha;
		rhash(zhi,X); Y=X;
		if(check(Y,B)==true)
		{
			flag=true;
			printf("%d\n",time);
			return ;
		}
		///LEFT
		LEFT(X);
		ha=hash(X);
		if(st[ha]==false)
		{
			st[ha]=true;
			q.push(ha);
			qt.push(time+1);
		}

		///Right
		X=Y;
		RIGHT(X);
		ha=hash(X);
		if(st[ha]==false)
		{
			st[ha]=true;
			q.push(ha);
			qt.push(time+1);
		}

		///UP
		X=Y;
		UP(X);
		ha=hash(X);
		if(st[ha]==false)
		{
			st[ha]=true;
			q.push(ha);
			qt.push(time+1);
		}

		///DOWN
		X=Y;
		DOWN(X);
		ha=hash(X);
		if(st[ha]==false)
		{
			st[ha]=true;
			q.push(ha);
			qt.push(time+1);
		}
	}
	if(flag==false) puts("-1");
}

int main()
{
	int x;
	while(scanf("%d",&x)!=EOF)
	{
		A.face[0]=x;
		for(int i=1;i<6;i++) scanf("%d",&A.face[i]);
		for(int i=0;i<6;i++) scanf("%d",&B.face[i]);

		if(checkIMP(A,B)==false)
		{
			puts("-1"); continue;
		}
		init(A); init(B);
		if(check(A,B)==true)
		{
			puts("0"); continue;
		}
		bfs();
	}
	return 0;
}