HDU 2102 A计划
该题是一道典型的搜索题，
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct Node
{
int x, y;
int time;
int flag;
}q[100024];
int d[4][2]={ 0,1,1,0,0,-1,-1,0 };
int N,M;
char map[2][13][13];
void getxy( int &X,int &Y,int &K )
{
for( int k=0;k<2;k++ )
for( int i=1;i<=N;i++ )
for( int j=1;j<=M;j++ )
{
if( map[k][i][j]=='S' )
{
K=k;
X=i;
Y=j;
return ;
}
}
}
int push( int x,int y,int time,int flag,int end )
{
Node t;
t.x=x; t.y=y;
t.time=time;
t.flag=flag;
q[end++]=t;
return end;
}
bool judge( int x,int y,int flag,int time )
{
if( map[flag][x][y]!=0 && map[flag][x][y]!='*'&&time>=0 )
return true;
else return false;
}
bool BFS( int x,int y,int k,int time )
{
int hash[2][14][14]={0},first=0,end=0;
end=push( x,y,time,k,end );
hash[k][x][y]=1;
while( first<end )
{
if( map[q[first].flag][q[first].x][q[first].y]=='P' )
return true;
for( int i=0;i<4;i++ )
{
int dx=q[first].x + d[i][0];
int dy=q[first].y + d[i][1];
int flag=q[first].flag;
int time=q[first].time-1;
if( judge( dx,dy,flag,time )&&!hash[flag][dx][dy] )
{
if( map[flag][dx][dy]!='#' )
{
if( map[flag][dx][dy]=='P' )
{
return true;
}
end=push( dx,dy,time,flag,end );
}
hash[flag][dx][dy]=1;
if( map[flag][dx][dy]=='#'&&!hash[(flag+1)%2][dx][dy])
if(map[( flag +1 )%2][dx][dy]!='*'&&map[(flag +1 )%2][dx][dy]!='#' )
{
if( map[( flag +1 )%2][dx][dy]=='P' )
return true;
hash[( flag+1 )%2][dx][dy]=1;
end=push( dx,dy,time,(flag+1)%2,end ) ;
}
}
}
first++;
}
return false;
}
int main()
{
int n,T,X,Y,K;
scanf( "%d",&n );
while( n-- )
{
memset( map,0,sizeof( map ) );
scanf( "%d%d%d",&N,&M,&T );
for( int k=0;k<2;k++ )
for( int i=1;i <= N; i++ )
{
scanf( "%s",map[k][i]+1 );
}
getxy( X,Y,K );
if( BFS( X,Y,K,T ) )
printf( "YES\n" );
else printf( "NO\n" );
}
}
代码2：
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
class Node
{
public:
int floor,x,y,time;
};
Node queue[1024];
char map[2][14][14];
int d[4][2]={ 0,1,1,0,0,-1,-1,0 };
bool BFS( int time )
{
int first = 0 , end = 0;
Node t;
t.x = 1;
t.y = 1;
t.time = 0;
t.floor = 0;
queue[end] = t;
end++;
map[0][1][1] = '*';
while( first < end )
{
t = queue[first];
int T = t.time+1;
if(time>=T)
{
for( int i = 0; i< 4 ; i++ )
{
int dx = t.x + d[i][0];
int dy = t.y + d[i][1];
if( map[t.floor][dx][dy]=='#'||map[t.floor][dx][dy]=='.'||map[t.floor][dx][dy]=='P' )
{
// if( t.floor==1 ) printf( "%d %d %d time=%d\n",t.floor,dx ,dy ,t.time);
if( map[t.floor][dx][dy]=='P' )
{
return true;
}
if( map[t.floor][dx][dy]=='#' )
{
if(map[(t.floor+1)%2][dx][dy]!='*'&&map[(t.floor+1)%2][dx][dy]!='#')
{
// printf( "%d %d %d time=%d\n",t.floor,dx ,dy ,T);
if( map[(t.floor+1)%2][dx][dy]=='P' )
{
return true;
}
else
{
queue[end].time = T;
queue[end].x = dx;
queue[end].y = dy;
queue[end].floor = (t.floor+1)%2;
map[(t.floor+1)%2][dx][dy]='*';
end++;
}
map[t.floor][dx][dy] = '*';
}
}
if( map[t.floor][dx][dy]=='.' )
{
map[t.floor][dx][dy]='*';
queue[end].time = T;
queue[end].x = dx;
queue[end].y = dy;
queue[end].floor = t.floor;
end++;
}
}
}
}
first++;
}
return false;
}
int main( )
{
int Case,n,m,time;
while( scanf( "%d",&Case )==1 )
{
while( Case -- )
{
memset( map , 0 ,sizeof( map ) );
scanf( "%d%d%d",&n , &m ,&time );
for( int i = 0; i<2 ; i++ )
{
for( int j=1 ; j<= n ; j++ )
scanf( "%s",map[i][j]+1 );
}
if( BFS( time ) )
printf( "YES\n" );
else printf( "NO\n" );
}
}
return 0;
}