UVA 321 - The New Villa BFS+位运算

状态总数10*2^10=10240,hash判重即可

注意点：在A房间不能关掉自己房间的灯（oh，my god，太伤了！）

 

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
int r,d,s,sum;
bool map[11][11],sw[11][11];
bool visit[11][1100];
int type[11][1100];  // move 1   on 2    off 3
int before[11][1100];
int beforestate[11][1100];
struct point{
	int room;
	int state;
	int step;
};
void bfs(){
	int i;
	queue<struct point>que;
	struct point sta;
	sta.room=1;
	sta.state=1;
	sta.step=0;
	visit[1][1]=1;
	que.push(sta);
	while(!que.empty()){
		struct point tem=que.front();
		que.pop();
                for(i=1;i<=r;i++){
			if(i==tem.room || !map[tem.room][i])
				continue;
			if(!(tem.state&(1<<(i-1))))
				continue;
			if(visit[i][tem.state])
				continue;
			struct point tmp;
			visit[i][tem.state]=1;

			type[i][tem.state]=1;
			before[i][tem.state]=tem.room;
			beforestate[i][tem.state]=tem.state;

			tmp.room=i;
			tmp.state=tem.state;
			tmp.step=tem.step+1;
			if(tmp.room==r && tmp.state==(1<<(r-1))){
				sum=tmp.step;
				return ;
			}
			que.push(tmp);
		}

		for(i=1;i<=r;i++){
			if(i==tem.room || !sw[tem.room][i])
				continue;
			int cur=tem.state^(1<<(i-1));
			if(visit[tem.room][cur])
				continue;
			visit[tem.room][cur]=1;

			if((tem.state&(1<<(i-1))))
				type[tem.room][cur]=3;
			else
				type[tem.room][cur]=2;
			before[tem.room][cur]=i;
			beforestate[tem.room][cur]=tem.state;

			struct point tmp;
			tmp.room=tem.room;
			tmp.state=cur;
			tmp.step=tem.step+1;
			if(tmp.room==r && tmp.state==(1<<(r-1))){
				sum=tmp.step;
				return ;
			}
			que.push(tmp);
		}
	}
}
void print_path(int state,int room){
	if(room==1 && state==1)
		return;
	if(type[room][state]==1){
		print_path(state,before[room][state]);
		printf("- Move to room %d.\n",room);
	}
	else if(type[room][state]==2){
		print_path(beforestate[room][state],room);
		printf("- Switch on light in room %d.\n",before[room][state]);
	}
	else if(type[room][state]==3){
		print_path(beforestate[room][state],room);
		printf("- Switch off light in room %d.\n",before[room][state]);
	}
}
int main(){
	int i,u,v,ca=0;
	while(scanf("%d %d %d",&r,&d,&s) && !(r==0 && d==0 && s==0)){
		printf("Villa #%d\n",++ca);
		sum=0;
		memset(map,0,sizeof(map));
		memset(sw,0,sizeof(sw));
		memset(visit,0,sizeof(visit));
		for(i=1;i<=d;i++){
			scanf("%d %d",&u,&v);
			map[u][v]=map[v][u]=1;
		}
		for(i=1;i<=s;i++){
			scanf("%d %d",&u,&v);
			sw[u][v]=1;
		}
		bfs();
		if(!visit[r][1<<(r-1)]){
			printf("The problem cannot be solved.\n");
		}
		else{
			printf("The problem can be solved in %d steps:\n",sum);
			print_path(1<<(r-1),r);
		}
		printf("\n");
	}
	return 0;
}