Submission #738947

#	Time	Username	Problem	Language	Result	Execution time	Memory
738947		He_Huanglu	Maze (JOI23_ho_t3)	C++17	62 / 100	573 ms	775208 KiB

Main

#include <bits/stdc++.h>
#define ii pair<int, int>
#define fi first
#define se second
using namespace std;

const int N = 6e6 + 5;
int n, m, s, rs, cs, re, ce;
int dx[4] = {0, -1, 0, 1};
int dy[4] = {-1, 0, 1, 0};
vector <int> f[N], a[N], p[2][N], ok[N];
queue <ii> q[2];

void upd(int t, int id, int i, int j, int val) {
    for(int x = i; x <= j; x++) {
        if(t) {
            if(!f[id][x]) q[1].push({id, x}), f[id][x] = val;
        }
        else {
            if(!f[x][id]) q[1].push({x, id}), f[x][id] = val;
        }
    }
}

main () {
    cin.tie(0)->sync_with_stdio(0);
    if(fopen("task.inp", "r")) {
        freopen("task.inp", "r", stdin);
        freopen("wa.out", "w", stdout);
    }
    cin >> m >> n >> s >> rs >> cs >> re >> ce;
    for(int i = 1; i <= m; i++) a[i].resize(n + 1), f[i].resize(n + 1), ok[i].resize(n + 1);
    for(int i = 1; i <= m; i++) {
        for(int j = 0; j <= n + 1; j++) p[1][i].push_back(j);
    }
    for(int i = 1; i <= n; i++) {
        for(int j = 0; j <= m + 1; j++) p[0][i].push_back(j);
    }
    for(int i = 1; i <= m; i++) {
        for(int j = 1; j <= n; j++) {
            char ch; cin >> ch;
            a[i][j] = (ch == '.' ? 1 : 0);
        }
    }
    q[1].push({rs, cs}); f[rs][cs] = 1;
    while (!q[1].empty() || !q[0].empty()) {
        while (!q[1].empty()) {
            int x, y; tie(x, y) = q[1].front(); q[1].pop();
            q[0].push({x, y});
//            cout << x << " " << y << " " << f[x][y] << " $$\n";
            if(x == re && y == ce) return cout << f[x][y] - 1 << "\n", 0;
            for(int i = 0; i < 4; i++) {
                int u = x + dx[i], v = y + dy[i];
                if(u && u <= m && v && v <= n && !f[u][v] && a[u][v]) {
//                    cout << x << " " << y << " : " << u << " " << v << "\n";
                    f[u][v] = f[x][y];
                    q[1].push({u, v});
//                    cout << u << " " << v << "*\n";
                }
            }
        }
        while (!q[0].empty()) {
            int x, y; tie(x, y) = q[0].front(); q[0].pop();
            if(s != 1) {
                if(x == rs && y == cs) {
                    int s1 = max(1, x - s), s2 = max(1, y - s);
                    int s3 = min(m, x + s), s4 = min(n, y + s);
                    for(int i = s1; i <= s3; i++) {
                        for(int j = s2; j <= s4; j++) if(!f[i][j]) {
                            f[i][j] = f[x][y] + 1;
                            q[1].push({i, j});
                        }
                    }
                }
                else {
                    int val = f[x][y] + 1;
                    upd(0, min(n, y + s), max(1, x - s), min(m, x + s), val);
                    upd(1, min(m, x + s), max(1, y - s), min(n, y + s), val);
                    upd(0, max(1, y - s), max(1, x - s), min(m, x + s), val);
                    upd(1, max(1, x - s), max(1, y - s), min(n, y + s), val);
                }
            }
            else {
                for(int i = 0; i < 4; i++) {
                    int u = x + dx[i], v = y + dy[i];
                    if(u && u <= m && v && v <= n && !f[u][v]) {
                        f[u][v] = f[x][y] + 1;
                        q[1].push({u, v});
//                        cout << u << " " << v << " ****\n";
                    }
                }
            }
        }
    }
}

Compilation message (stderr)

Main.cpp:25:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main () {
      | ^~~~
Main.cpp: In function 'int main()':
Main.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen("task.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen("wa.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 16 / 16
• Subtask 4: 19 / 19
• Subtask 5: 0 / 5
• Subtask 6: 0 / 19
• Subtask 7: 0 / 8
• Subtask 8: 0 / 6