版权声明: https://blog.csdn.net/qq_40829288/article/details/83716348
//Knight Moves : http://poj.org/problem?id=1915
#include<iostream>
#include<cstring>
#include<queue>
using namespace std;
int l,sx,sy,ex,ey;
bool mark[305][305];
int go[8][2]={-2,1,-1,2,1,2,2,1,2,-1,1,-2,-1,-2,-2,-1};
struct node
{
int x,y,step;
};
void bfs()
{
memset(mark,0,sizeof(mark));
mark[sx][sy] = 1;
queue<node> q;
node s,n; //n是一个坑点,如果不用n,只用s,会导致下一步的选择对当前步产生影响;
s.x = sx,s.y = sy,s.step = 0;
q.push(s);
while(!q.empty())
{
s = q.front();
q.pop();
if(s.x == ex&&s.y == ey)
{
cout<<s.step<<endl;
return ;
}
for(int i=0;i<8;i++)
{
int nx = s.x + go[i][0];
int ny = s.y + go[i][1];
if(nx<l&&ny<l&&nx>=0&&ny>=0&&!mark[nx][ny])
{
mark[nx][ny] = 1;
n.x = nx,n.y = ny; // 注意
n.step = s.step + 1; //注意
q.push(n); //注意
}
}
}
}
int main()
{
int T;
cin>>T;
while(T--)
{
cin>>l>>sx>>sy>>ex>>ey;
if(sx==ex&&sy==ey)
cout<<0<<endl;
else
bfs();
}
return 0;
}