uva 439

题意：模仿中国象棋的马走的方式，求从起点到终点的最少步数。。。

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

int maze[10][10];
int dir[8][2] ={{-2,-1},{-2,1},{2,-1},{2,1},{1,2},{1,-2},{-1,2},{-1,-2}};
int x1,x2,y2,y1;

void dfs(int x,int y,int step)
{
    if (x == x2 && y == y2)
        return ;

    for (int i = 0 ; i < 8 ; i++)
    {
        int nx = x + dir[i][0];
        int ny = y + dir[i][1];
        if (nx >= 0 && nx <=7 && ny >= 0 && ny <= 7 && (maze[nx][ny] == -1|| maze[nx][ny] > step))
        {
            maze[nx][ny] =step ;
            dfs(nx,ny,step+1);
        }
    }
}

int main()
{
    char str1[5],str2[5];
    while (scanf("%s%s",str1,str2) != EOF )
    {
        memset(maze,-1,sizeof(maze));
        x1 = str1[0]-97,x2 = str2[0]-97;
        y1 = str1[1]-49,y2 = str2[1]-49;
        maze[x1][y1] = 0 ;
        dfs(x1,y1,1);
        printf("To get from %s to %s takes %d knight moves.\n",str1,str2,maze[x2][y2]);                  
    }
    return 0;
}