题解

#include<bits/stdc++.h>
using namespace std;
struct p{
int x,y,step;
p();
p(int a,int b,int c){x=a;y=b;step=c;}
};
int n,m,x,y,mp[401][401],mo[8][2]={{1,-2},{1,2},{-1,2},{-1,-2},{2,-1},{-2,-1},{2,1},{-2,1}};
bool vis[401][401];
int main(){
    cin>>n>>m>>x>>y;
    queue<p>q;
    q.push(p(x,y,0));
    vis[x][y]=1;
    while(!q.empty()){
        p tmp=q.front();
        q.pop();
        for(int i=0;i<8;++i){
            int xx=tmp.x+mo[i][0],yy=tmp.y+mo[i][1];
            if(xx>=1&&yy>=1&&xx<=n&&yy<=m&&!vis[xx][yy]){
                vis[xx][yy]=1;
                mp[xx][yy]=tmp.step+1;
                q.push(p(xx,yy,tmp.step+1));
            }
        }
    }
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j){
            if(!vis[i][j])printf("-1 ");
            else printf("%d ",mp[i][j]);
        }
        printf("\n");
    }
    return 0;
}