1257：Knight Moves

Description [title]

Enter n

Representatives of a n- × n-

Board, the input start position and end position coordinates, asked a Knight of eight directions of the board cursory word step, from start to finish coordinate coordinate how many steps you can go through.

[Enter]

First, enter a n

It indicates the number of test samples.

Each test sample has three rows.

The first line is the size of the board L (4 ≦ L ≤300)

；

The second and third rows represent the horse starting position and the target position (0 .. L -1)

。

[Output]

Horse moves minimum number of steps, the starting position and the target position are the same output 0

。

[Sample input]

3
8
0 0
7 0
100
0 0
30 50
10
1 1
1 1

[Sample Output]

5
28
0

 

// Created on 2020/2/9

/*#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <climits>*/
#include <bits/stdc++.h>
#define MAXX 40*40+5

using namespace std;

//int i,j,k;

const int maxn=INT_MAX;

const int idata=100000+5;
//int aim[idata];
bool judge[305][305];
bool flag;
int soux,souy,
    exitx,exity;
//int maps[idata][idata];
const int change[8][2]={{2,1},{2,-1},{1,2},{1,-2},
                        {-2,1},{-2,-1},{-1,2},{-1,-2}};
int n,m;
int ans[idata];
int nx,ny;
int x[idata],y[idata];

int main()
{
    int head,tail;
    int i,j;
    int t;
    cin>>t;

    while(t--)
    {
        flag=0;
        memset(judge,0,sizeof(judge));
        cin>>n;

        cin>>soux>>souy;
        cin>>exitx>>exity;

        if(soux==exitx&&souy==exity)
        {
            cout<<0<<endl;
            continue;
        }

        head=0,tail=1;
        x[1]=soux,y[1]=souy;
        judge[soux][souy]=1;
        ans[1]=0;

        do
        {
            head++;

            for(i=0;i<8;i++)
            {
                nx=x[head]+change[i][0];
                ny=y[head]+change[i][1];

                if(nx>=0&&ny>=0&&nx<n&&ny<n
                   &&!judge[nx][ny])
                {
                    judge[nx][ny]=1;
                    tail++;
                    x[tail]=nx;
                    y[tail]=ny;
                    ans[tail]=ans[head]+1;
                }

                if(nx==exitx&&ny==exity)
                {
                    flag=1;
                    cout<<ans[tail]<<endl;
                    break;
                }
            }
            if(flag) break;

        }while(head<tail);

    }
    return 0;
}