广度优先搜索正经题解

#include<bits/stdc++.h>
using namespace std;
int n, m, x, y;
int g[500][500];
int dx[] = {2, -2, 1, -1, 2, -2, 1, -1};
int dy[] = {1, -1, 2, -2, -1, 1, -2, 2};
struct node{
    int x, y;
};
int main(){
    cin >> n >> m >> x >> y;
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            g[i][j]=1e9;
        }
    }
    queue<node> q;
    q.push({x, y});
    g[x][y]=0;
    while(q.size()){
        node u = q.front();
        q.pop();
        for(int i=0; i<8; i++){
            int nx = u.x+dx[i];
            int ny = u.y+dy[i];
            if(nx>=1&&nx<=n&&ny>=1&&ny<=m){
                if(g[nx][ny]>g[u.x][u.y]+1){
                    g[nx][ny]=g[u.x][u.y]+1;
                    q.push({nx, ny});
                }
            }
        }
    }
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            if(g[i][j]==1e9)printf("%-5d", -1);
            else printf("%-5d", g[i][j]);
        }
        cout << endl;
    }
}