UVA 439(p177)----Knight Moves

#include<iostream>
#include<cstdio>
#include<cstring>
const int dx[8] = {-2,-2,-1,-1,1,1,2,2};
const int dy[8] = {-1,1,-2,2,-2,2,-1,1};
typedef struct
{
    int x,y,st;
} point;
point q[10000];
char st[10],en[10];
int v[10][10];
using namespace std;
void solve(int xx,int yy,int xxx,int yyy)
{
    int head=0,tail=1;
    q[1].x=xx;
    q[1].y=yy;
    q[1].st=0;
    v[xx][yy]=true;
    while(head<=tail)
    {
        head++;
        for(int i=0; i<8; i++)
        {
            int x=q[head].x+dx[i];
            int y=q[head].y+dy[i];
            //cout<<x<<" "<<y<<endl;
            // cout<<x<<" "<<y<<endl;
            if(!v[x][y]&&x>=1&&x<=8&&y>=1&&y<=8)
            {
                tail++;
                q[tail].x=x;
                q[tail].y=y;
                q[tail].st=q[head].st+1;
                v[x][y]=true;

            }
            if(x==xxx&&y==yyy)
            {
                printf("To get from %s to %s takes %d knight moves.\n",st,en,q[tail].st);
                return;
            }

        }
    }
}
int main()
{
    while(scanf("%s%s",st,en)!=EOF)
    {
        int x,y,xx,yy;
        memset(q,0,sizeof(q));
        memset(v,0,sizeof(v));
        x=st[1]-'0';
        y=st[0]-'a'+1;
        xx=en[1]-'0';
        yy=en[0]-'a'+1;
        // cout<<x<<" "<<y<<" "<<xx<<" "<<yy<<endl;
        if(x==xx&&y==yy) printf("To get from %s to %s takes %d knight moves.\n",st,en,0);
        else
            solve(x,y,xx,yy);
    }

    return 0;

}

题目地址：https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=6&page=show_problem&problem=380