如果骑士可以走完所有格子,那一定可以走到a1,所以我们从a1开始深搜
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int path[88][88], vis[88][88], p, q, cnt;
bool flag;
//8种走法
int dx[8] = {
-1, 1, -2, 2, -2, 2, -1, 1 };
int dy[8] = {
-2, -2, -1, -1, 1, 1, 2, 2 };
//判断该点是否符合要求
bool judge(int x, int y)
{
if (x >= 1 && x <= p && y >= 1 && y <= q && !vis[x][y] && !flag)
return true;
return false;
}
void DFS(int r, int c, int step)
{
path[step][0] = r;//记录路径
path[step][1] = c;
if (step == p * q)
{
flag = true;
return;
}
for (int i = 0; i < 8; i++)
{
int nx = r + dx[i];
int ny = c + dy[i];
if (judge(nx, ny))
{
vis[nx][ny] = 1;
DFS(nx, ny, step + 1);
vis[nx][ny] = 0;
}
}
}
int main()
{
int i, j, n, cas = 0;
scanf("%d", &n);
while (n--)
{
flag = 0;
scanf("%d%d", &p, &q);
memset(vis, 0, sizeof(vis));
vis[1][1] = 1;
DFS(1, 1, 1);
printf("Scenario #%d:\n", ++cas);
if (flag)
{
for (i = 1; i <= p * q; i++)
printf("%c%d", path[i][1] - 1 + 'A', path[i][0]);
}
else
printf("impossible");
printf("\n");
if (n != 0)
printf("\n");
}
return 0;
}