| # | Time | Username | Problem | Language | Result | Execution time | Memory | 
|---|---|---|---|---|---|---|---|
| 1023300 | snpmrnhlol | Maze (JOI23_ho_t3) | C++17 | 0 ms | 0 KiB | 
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
using namespace std;
const int N = 6e6;
const int inf = 2e9;
int k,n,m,sx,sy,ex,ey;
int d[8][2] = {{1,0},{-1,0},{0,1},{0,-1},{1,1},{1,-1},{-1,1},{-1,-1}};
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int ans = inf;
    cin>>n>>m>>k;
    cin>>sx>>sy>>ex>>ey;
    vector<vector <char>> v(n + 2,vector<char>(m + 2,0));
    vector<vector <vector<bool>>> vis(n + 2,vector<vector<bool>>(m + 2,vector<bool>(2,0)));
    vector <array<int,2>> q;
    vector <array<int,3>> q2;
    for(int i = 0;i < n + 2;i++){
        v[i][0] = 2;
        v[i][m + 1] = 2;
    }
    for(int i = 0;i < m + 2;i++){
        v[0][i] = 2;
        v[n + 1][i] = 2;
    }
    for(int i = 0;i < n;i++){
        for(int j = 0;j < m;j++){
            char ch;
            cin>>ch;
            if(ch == '.'){
                v[i + 1][j + 1] = 0;
            }else{
                v[i + 1][j + 1] = 1;
            }
        }
    }
    vis[sx][sy][0] = 1;
    q.push_back({sx,sy});
    for(int i = 0;i <= n + m;i++){
        int pt = 0;
        q2.clear();
        while(pt < q.size()){
            auto x = q[pt];pt++;
            if(x[0] == ex && x[1] == ey){
                ans = i;
            }
            ///bfs
            if(!vis[x[0]][x[1]][1]){
                q2.push_back({x[0],x[1],0});
            }
            for(int j = 0;j < 4;j++){
                int nx = x[0] + d[j][0];
                int ny = x[1] + d[j][1];
                if(!vis[nx][ny][0] && v[nx][ny] == 0){
                    vis[nx][ny][0] = 1;
                    q.push_back({nx,ny});
                }
            }
        }
        q.clear();
        pt = 0;
        while(pt < q2.size()){
            auto x = q2[pt];
            pt++;
            if(!vis[x[0]][x[1]][0]){
                q.push_back({x[0],x[1]});
                vis[x[0]][x[1]][0] = 1;
            }
            if(x[2] != k - 1){
                for(int j = 0;j < 8;j++){
                    int nx = x[0] + d[j][0];
                    int ny = x[1] + d[j][1];
                    if(!vis[nx][ny][1] && v[nx][ny] != 2){
                        vis[nx][ny][1] = 1;
                        q2.push_back({nx,ny,x[2] + 1});
                    }
                }
            }else{
                for(int j = 0;j < 4;j++){
                    int nx = x[0] + d[j][0];
                    int ny = x[1] + d[j][1];
                    if(!vis[nx][ny][0] && v[nx][ny] != 2){
                        vis[nx][ny][0] = 1;
                        q.push_back({nx,ny});
                    }
                }
            }
        }
    }
    assert(pt + pt2 <= 2*N);
    cout<<ans<<'\n';
    return 0;
}
