Description

The knight is getting bored of seeing the same black and white squares again and again and has decided to make a journey
around the world. Whenever a knight moves, it is two squares in one direction and one square perpendicular to this. The world of a knight is the chessboard he is living on. Our knight lives on a chessboard that has a smaller area than a regular 8 * 8 board, but it is still rectangular. Can you help this adventurous knight to make travel plans?
Problem
Find a path such that the knight visits every square once. The knight can start and end on any square of the board.
Input
The input begins with a positive integer n in the first line. The following lines contain n test cases. Each test case consists of a single line with two positive integers p and q, such that 1 <= p * q <= 26. This represents a p * q chessboard, where p describes how many different square numbers 1, . . . , p exist, q describes how many different square letters exist. These are the first q letters of the Latin alphabet: A, . . .
Output
The output for every scenario begins with a line containing "Scenario #i:", where i is the number of the scenario starting at 1. Then print a single line containing the lexicographically first path that visits all squares of the chessboard with knight moves followed by an empty line. The path should be given on a single line by concatenating the names of the visited squares. Each square name consists of a capital letter followed by a number.
If no such path exist, you should output impossible on a single line.
If no such path exist, you should output impossible on a single line.
Sample Input
3 1 1 2 3 4 3
Sample Output
Scenario #1: A1 Scenario #2: impossible Scenario #3: A1B3C1A2B4C2A3B1C3A4B2C4
—————————————————————————————————————————————————————————————————————————————
分界线
—————————————————————————————————————————————————————————————————————————————
这个题很明显是深搜的问题 第一次wa是因为一些细节原因(复制粘贴惹的祸) 第二次是字母表的顺序没调对,最后一次 得怪可恶的空行!!!!!!!!!!!
下面就是代码了 注意字母表的规律的时候一定要注意+2 +1的细节之差.....(说多了都是泪)
#define _CRT_SECURE_NO_WARNINGS//vs防报错 scanf不安全....
#include<cstdio>
#include<cstring>
int vis[100][100];
int a, b, i, j, flag;
void trav(int x, int y, int n)
{
int o;
if (flag == 1)return;//一旦找到就退出
if (vis[x][y] == 0 && x >= 1 && x <= a&&y >= 1 && y <= b){//判定是否在局内
if (n >= a*b&&flag != 1){//找到了就出结果
vis[x][y] = n;
flag = 1;
for (o = 1; o <= a*b; o++){
for (i = 1; i <= a; i++){
for (j = 1; j <= b; j++){
if (vis[i][j] == o)printf("%c%d", i + 'A' - 1, j);//vis记录数据 这样可能导致计算的时候效率低下 可以采用struct来弥补这个问题
}
}
}
printf("\n");
}
vis[x][y] = n;//标记为已经寻的
n++;
trav(x - 2, y - 1, n);
trav(x - 2, y + 1, n);
trav(x - 1, y - 2, n);
trav(x - 1, y + 2, n);
trav(x + 1, y - 2, n);
trav(x + 1, y + 2, n);
trav(x + 2, y - 1, n);
trav(x + 2, y + 1, n);//8方向遍历
vis[x][y] = 0;//如果什么都不成功 返回到上一步
}
return;
}
int main()
{
int i, n;
//freopen("test.txt", "r", stdin);
scanf("%d", &n);
for (i = 0; i<n; i++){
scanf("%d%d", &b, &a);
flag = 0;
printf("Scenario #%d:\n", i + 1);
memset(vis, 0, sizeof(vis));
trav(1, 1, 1);
if (flag == 0)printf("impossible\n");
if(i!=n-1)printf("\n");//唯有泪千行!!!!!!!!一定!!!!!!
}
return 0;
}