Knight Moves

#include<bits/stdc++.h>
using namespace std;
#define max_v 10
int G[max_v][max_v];
int dir[8][2]= {{1,-2},{2,-1},{2,1},{1,2},{-1,2},{-2,1},{-2,-1},{-1,-2}};
int step;
int sx,sy,fx,fy;
struct node
{
    int x,y,step;
};
void bfs()
{
    memset(G,0,sizeof(G));
    queue<node> q;
    node p,next;
    p.x = sx;
    p.y = sy;
    p.step = 0;
    G[p.x][p.y] = 1;
    q.push(p);

    while(!q.empty())
    {
        p = q.front();
        q.pop();

        if(p.x == fx&&p.y == fy)
        {
            step = p.step;
            return ;
        }

        for(int i = 0;i < 8; i ++)
        {
            next.x = p.x + dir[i][0];
            next.y = p.y + dir[i][1];

            if(next.x >= 1 && next.y >= 1 && next.x <= 8 && next.y <= 8 && G[next.x][next.y] ==0)
            {
                next.step=p.step+1;
                G[next.x][next.y]=1;
                q.push(next);
            }
        }
    }
}
int main()
{
    char c1,c2;
    int y1,y2;
    while(scanf("%c%d %c%d",&c1,&y1,&c2,&y2))
    {
        getchar();
        sx=c1-'a'+1;
        sy=y1;
        fx=c2-'a'+1;
        fy=y2;
        bfs();
        cout << step << endl;
        return 0; 
    }
    return 0;
}