P2895 Meteor Shower S，DFS写法大佬求助感觉思路是对的

#include <cstring>
#define N 310
using namespace std;
int m,t[N][N],s[N][N];
int ex[4] = {0,-1,1,0},ey[4] = {1,0,0,-1};
void dfs(int x,int y,int t){
    cout << x <<" "<< y<<" " << t << endl;
    //int nt = t[x][y];
    //cout <<endl <<  x <<" "<< y;
    if(s[x][y] == -1){
        /*for(int i = 0;i < 5;i++){
            for(int j = 0;j < 5;j++){
                cout << t[i][j] << " ";
            }
            cout << endl;
        }
        cout << endl;*/
        cout << t;
        return;
    }
    for(int i = 0;i < 4;i++){
        int dx = x + ex[i],dy = y + ey[i];
        //cout << dx << " " <<  dy << endl;
        if(dx >= 0 && dy >= 0 && s[dx][dy] > t){
            //int cnt = t[dx][dy];
            //t[dx][dy] == nt + 1;
            dfs(dx,dy,t+1);
            //t[dx][dy] == cnt;
        }
    }
}
int main(){
    cin >> m;
    memset(s,-1,sizeof s);
    for(int i = 1;i <= m;i++){
        int xx,yy,tt;
        cin >> xx >> yy >> tt;
        if(s[xx][yy] == -1){
            s[xx][yy] = tt;
        }else{
            s[xx][yy] = min(s[xx][yy],tt);
        } 
        for(int i = 0;i < 4;i++){
            int dx = xx + ex[i],dy = yy + ey[i];
            if(dx >= 0 && dy >= 0){
                if(s[dx][dy] == -1){
                    s[dx][dy] = tt;
                }else{
                    s[dx][dy] = min(s[dx][dy],tt);
                } 
            }
        }
    }
    //t[0][0] = 0;
    cout << endl;
    dfs(0,0,0);
    cout << endl;
    for(int i = 0;i < 5;i++){
        for(int j = 0;j < 5;j++){
            cout << s[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}