hdu 1372 Knight Moves

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
struct node
{
    int x;
    int y;
    int step;
} cur,next,st,ed;
int dir[8][2]= {-1,-2,-2,-1,-2,1,-1,2,1,2,2,1,2,-1,1,-2};
char start[4],end[4];
int map[10][10];
queue<node>q;
int judge(int x,int y)
{
    if(x<0||x>7||y<0||y>7)return 1;
    if(map[x][y])return 1;
    return 0;
}
int BFS()
{
    int i;
    int step=0;
    memset(map,0,sizeof(map));
    while(!q.empty())q.pop();
    st.x=start[0]-'a';
    st.y=start[1]-'1';
    st.step=0;
    ed.x=end[0]-'a';
    ed.y=end[1]-'1';
    q.push(st);
    while(!q.empty())
    {
        cur=q.front();
        q.pop();
        if(cur.x==ed.x&&cur.y==ed.y)return step;
        for(i=0; i<8; i++)
        {
            next.x=cur.x+dir[i][0];
            next.y=cur.y+dir[i][1];
            if(judge(next.x,next.y))continue;
            if(next.x==ed.x&&next.y==ed.y)return cur.step+1;
            next.step=cur.step+1;
            map[next.x][next.y]=1;
            q.push(next);
        }
        //step++;
    }
    return 0;
}
int main()
{
    while(scanf("%s %s",start,end)!=EOF)
    {
        //printf("%s %s\n",start,end);
        int ans=BFS();
        printf("To get from %s to %s takes %d knight moves.\n",start,end,ans);
        memset(start,0,sizeof(start));
        memset(end,0,sizeof(end));
    }
    return 0;
}

题意为马走日，典型的BFS搜索@#@