#include <string.h>
const int maxn = 50;
int b[8]={-2, -2, -1, -1, 1, 1, 2, 2},a[8]={-1, 1, -2, 2, -2, 2, -1, 1};
bool check[maxn][maxn], flag;
int ansx[maxn], ansy[maxn];
int row, col;
void dfs(int x, int y, int sum)
{
if(sum == col * row)
{
for(int i=1; i<=sum; i++)
printf("%c%d", ansy[i]+'A'-1, ansx[i]);
printf("\n");
flag=1;
return;
}
for(int i=0; i<8 && !flag; i++)
{
if(!flag && !check[x+a[i]][y+b[i]] && x+a[i]>0 && x+a[i]<=row && y+b[i]>0 && y+b[i]<=col)
{
ansx[sum+1] = x+a[i];
ansy[sum+1] = y+b[i];
check[x+a[i]][y+b[i]] = 1;
dfs(x+a[i], y+b[i], sum+1);
check[x+a[i]][y+b[i]] = 0;
}
}
}
int main()
{
int n;
int cas;
while(~scanf("%d",&n))
{
cas=1;
while(n--)
{
flag = 0;
memset(check,0,sizeof(check));
printf("Scenario #%d:\n",cas++);
scanf("%d%d", &row, &col);
check[1][1]=1;
ansx[1] = ansy[1] = 1;
dfs(1, 1, 1);
if(!flag) printf("impossible\n");
printf("\n");
}
}
return 0;
}
]]>
#include <cstdio>
#include <cmath>
const int maxn = 10;
using namespace std;
bool escape;
char map[maxn][maxn];
int dir[4][2] = {{-1,0}, {1,0}, {0,-1}, {0,1}};
int n, m, t;
int si, sj, di, dj;
void dfs( int x, int y, int cnt )
{
if( escape ) return;
if( x == di && y == dj && cnt == t )
{
escape = 1;
return;
}
int temp = t - cnt - ( fabs(di - x) + fabs(dj - y ) );
if( temp < 0 || temp % 2 != 0 ) return;//濂囧伓鍓灊
if( x <= 0 || y <= 0 || x > n || y > m ) return;
for( int i = 0; i < 4; i++ )
{
if( map[x+dir[i][0]][y+dir[i][1]] != 'X')
{
map[x+dir[i][0]][y+dir[i][1]] = 'X';
dfs(x+dir[i][0], y+dir[i][1], cnt+1);
map[x+dir[i][0]][y+dir[i][1]] = '.';
}
}
}
int main()
{
while( cin >> n >> m >> t, m || n || t )
{
int wall = 0;
escape = 0;
for ( int i = 1; i <= n; i++ )
for ( int j = 1; j <= m; j++ )
{
cin >> map[i][j];
if( map[i][j] == 'D')
{
di = i;
dj = j;
}
else if ( map[i][j] == 'S' )
{
si = i;
sj = j;
}
else if ( map[i][j] == 'X' )
wall ++ ;
}
if( m * n - wall <= t )
{
printf("NO\n");
continue;
}
else
{
map[si][sj] = 'X';
dfs( si, sj, 0 );
printf("%s\n", escape ? "YES" : "NO" );
}
}
return 0;
}
]]>