输入：3 5 19 19
输出：2 2
by mediocre_ @ 2023-04-11 19:24:09
你的队列q在第二次循环的时候没有清空
```cpp
#include<bits/stdc++.h>
using namespace std;
const int N = 20 + 9;
const int fx[] = {1, 1, 2, 2, 2, 2, -1, -1, -2, -2, -2, -2};
const int fy[] = {-2, 2, -2, -1, 1, 2, -2, 2, -1, 1, -2, 2};
int x, y;
int vis[N][N];
bool use[N][N];
struct Node {
int x, y;
};
queue <Node>q;
bool inmap(int nx, int ny) {
return nx >= 1 && nx <= 20 && ny >= 1 && ny <= 20;
}
int main() {
for (int i = 1; i <= 2; ++i) {
memset(vis, 0, sizeof vis);
memset(use, 0, sizeof use);
while (!q.empty()) q.pop();//就是这！！！
scanf("%d%d", &x, &y);
q.push(Node{x, y});
use[x][y] = true;
while (!q.empty()) {
Node u = q.front();
q.pop();
if (u.x == 1 && u.y == 1) {
printf("%d\n", vis[1][1]);
break;
}
for (int d = 0; d < 12; d++) {
int nx = u.x + fx[d];
int ny = u.y + fy[d];
if (inmap(nx, ny) && !use[nx][ny]) {
vis[nx][ny] = vis[u.x][u.y] + 1;
use[nx][ny] = true;
q.push(Node{nx, ny});
}
}
}
/*for (int j = 1; j <= 20; ++j) {
for (int k = 1; k <= 20; ++k)
printf("%d ", vis[j][k]);
printf("\n");
}*/
}
return 0;
}
```
by Creeper250 @ 2023-05-18 22:56:12
@[Mr_Huang12](/user/565707)
我把要加的补在了main函数第4行
by Creeper250 @ 2023-05-19 19:35:00
手打队列存图：
```cpp
#include<bits/stdc++.h>
using namespace std;
int flag[25][25],startx,starty;
struct queue{
int x,y,s=0;
}que[1005];
int dx[12]={-1,-2,-2,-2,-2,-1,1,2,2,2,2,1};
int dy[12]={-2,-2,-1,1,2,2,2,2,1,-1,-2,-2};
bool check(int p,int q)
{
if(p<1||p>20||q<1||q>20)
return false;
return true;
}
void bfs()
{
int head=0,tail=1;
while(head<tail)
{
head++;
for(int i=0;i<12;i++)
{
int nx=dx[i]+que[head].x;
int ny=dy[i]+que[head].y;
if(check(nx,ny)==true&&flag[nx][ny]==0)
{
tail++;
flag[nx][ny]=1;
que[tail].x=nx;
que[tail].y=ny;
que[tail].s=que[head].s+1;
if(nx==1&&ny==1)
{
cout<<que[tail].s<<endl;
return;
}
}
}
}
}
int main()
{
for(int i=1;i<=2;i++)
{
memset(flag,0,sizeof(flag));
memset(que,0,sizeof(que));
cin>>startx>>starty;
que[1].x=startx;
que[1].y=starty;
flag[startx][starty]=1;
bfs();
}
return 0;
}
```
by poor_OIer @ 2023-05-27 22:16:00