Submission #1023242

#	Time	Username	Problem	Language	Result	Execution time	Memory
1023242		snpmrnhlol	Maze (JOI23_ho_t3)	C++17	100 / 100	1836 ms	1573784 KiB

Main

#include<bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
const int N = 6e6;
const int inf = 2e9;
vector <char> v[N];
vector <vector<bool>> vis[N];
int k,n,m,sx,sy,ex,ey;
queue <array<int,2>> q[2];
queue <array<int,3>> q2;
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;
    for(int i = 0;i < n + 2;i++){
        v[i].assign(m + 2,0);
        vis[i].assign(m + 2,vector<bool>(2,0));
        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[0].push({sx,sy});
    for(int i = 0;i <= n + m;i++){
        while(!q[i%2].empty()){
            auto x = q[i%2].front();
            q[i%2].pop();
            if(x[0] == ex && x[1] == ey){
                ans = i;
            }
            ///bfs
            if(!vis[x[0]][x[1]][1]){
                q2.push({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[i%2].push({nx,ny});
                }
            }
        }
        while(!q2.empty()){
            auto x = q2.front();
            q2.pop();
            if(!vis[x[0]][x[1]][0]){
                q[(i%2)^1].push({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({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[(i%2)^1].push({nx,ny});
                    }
                }
            }
        }
    }
    cout<<ans<<'\n';
    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 16 / 16
• Subtask 4: 19 / 19
• Subtask 5: 5 / 5
• Subtask 6: 19 / 19
• Subtask 7: 8 / 8
• Subtask 8: 6 / 6