poj1915

简单题

View Code

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <queue>
using namespace std;

struct XPoint
{
int x, y;
int step;

} s, e;

#define maxn 306

int n;
bool vis[maxn][maxn];
int dir[8][2] =
{
{ 1, 2 },
{ 2, 1 },
{ -1, 2 },
{ -2, 1 },
{ -1, -2 },
{ -2, -1 },
{ 1, -2 },
{ 2, -1 } };

bool ok(XPoint &b)
{
if (b.x < 0 || b.y < 0 || b.x >= n || b.y >= n)
return false;
return !vis[b.x][b.y];
}

void bfs()
{
queue<XPoint> q;
s.step = 0;
q.push(s);
memset(vis, 0, sizeof(vis));
vis[s.x][s.y] = true;
while (!q.empty())
{
XPoint a = q.front();
q.pop();
for (int i = 0; i < 8; i++)
{
XPoint b;
b.x = a.x + dir[i][0];
b.y = a.y + dir[i][1];
b.step = a.step + 1;
if (ok(b))
{
vis[b.x][b.y] = true;
q.push(b);
}
if (b.x == e.x && b.y == e.y)
{
printf("%d\n", b.step);
return;
}
}
}
}

int main()
{
// freopen("t.txt", "r", stdin);
int t;
scanf("%d", &t);
while (t--)
{
scanf("%d", &n);
scanf("%d%d", &s.x, &s.y);
scanf("%d%d", &e.x, &e.y);
if (s.x == e.x && s.y == e.y)
{
printf("0\n");
continue;
}
bfs();
}
return 0;
}