poj1915

#include<iostream>
using namespace std;
#define SIZE 305

int vis[SIZE][SIZE];
int sx,sy,ex,ey;
int dx[8]={-1,-2,-2,-1,1,2,2,1};
int dy[8]={-2,-1,1,2,2,1,-1,-2};
int n,case_num;
typedef struct node
{
    int x;
    int y;
    int step;
}node;
node queue[SIZE*SIZE];

void bfs()
{
    int head,tail;
    head=tail=0;
    node startnode;
    startnode.x=sx;
    startnode.y=sy;
    startnode.step=0;
    queue[tail++]=startnode;
    vis[startnode.x][startnode.y]=1;
    node cur,next;
    while(head!=tail)
    {

        int nx,ny;
        cur=queue[head++];
        if(cur.x==ex&&cur.y==ey)
        {
            cout<<cur.step<<endl;
            return;
        }
        for(int i=0;i<8;i++)
        {
            nx=cur.x+dx[i];
            ny=cur.y+dy[i];
            if(nx>=0&&nx<n&&ny>=0&&ny<n&&vis[nx][ny]==0)
            {
                next.x=nx;
                next.y=ny;
                next.step=cur.step+1;
                queue[tail++]=next;
                vis[next.x][next.y]=1;
            }
        }
    }
}
int main()
{
    //freopen("input.txt","r",stdin);
    cin>>case_num;
    while(case_num--)
    {
        cin>>n;
        cin>>sx>>sy>>ex>>ey;
        for(int i=0;i<n;i++)
            for(int j=0;j<n;j++)
                vis[i][j]=0;
        bfs();
    }
    return 0;
}