POJ 2488 A Knight's Journey

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <climits>
 7 #include <vector>
 8 #include <queue>
 9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #include <stack>
13 #define LL long long
14 #define pii pair<int,int>
15 #define INF 0x3f3f3f3f
16 using namespace std;
17 const int dir[8][2] = {{-2,-1},{-2,1},{-1,-2},{-1,2},{1,-2},{1,2},{2,-1},{2,1}};
18 int n,m,path[100][2];
19 bool vis[100][100];
20 bool dfs(int x,int y,int cur){
21     if(cur >= n*m) return true;
22     for(int i = 0; i < 8; i++){
23         int tx = dir[i][0]+x;
24         int ty = dir[i][1]+y;
25         if(tx < 0 || tx >= n || ty < 0 || ty >= m || vis[tx][ty]) continue;
26         vis[tx][ty] = true;
27         path[cur][0] = tx+‘A‘;
28         path[cur][1] = ty+1;
29         if(dfs(tx,ty,cur+1)) return true;
30         vis[tx][ty] = false;
31     }
32     return false;
33 }
34 int main() {
35     int t,k = 1;
36     scanf("%d",&t);
37     while(t--){
38         scanf("%d %d",&m,&n);
39         bool flag = false;
40         memset(vis,false,sizeof(vis));
41         path[0][0] = ‘A‘;
42         path[0][1] = 1;
43         vis[0][0] = true;
44         printf("Scenario #%d:\n",k++);
45         if(dfs(0,0,1)){
46             for(int i = 0; i < n*m; i++) printf("%c%d",path[i][0],path[i][1]);
47             puts("");
48         }else puts("impossible");
49         puts("");
50     }
51     return 0;
52 }