Submission #1294047

#	Time	Username	Problem	Language	Result	Execution time	Memory
1294047		thaibeo123	Bitaro's travel (JOI23_travel)	C++20	0 / 100	1 ms	332 KiB

travel

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define NAME "A"
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define MASK(x) (1ll << (x))
#define BIT(x, i) (((x) >> (i)) & 1)

const int inf = 1e18;

int n, m, q, L;
vector<vector<int>> a;
int dx[] = {0, -1, 0, 1};
int dy[] = {-1, 0, 1, 0};

bool inside(int x, int y) {
    return 1 <= x && x <= n && 1 <= y && y <= m;
}

void input() {
    cin >> n >> m >> L;
    a.assign(n + 1, vector<int>(m + 1));
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
        }
    }
}

namespace subtask1 {
    vector<vector<pair<int, int>>> mx;
    vector<vector<vector<vector<bool>>>> d;

    bool check() {
        return n <= 3000;
    }

    void bfs(vector<vector<bool>> &d, int u, int v) {
        queue<pair<int, int>> q;
        d[u][v] = 1;
        q.push({u, v});
        while (q.size()) {
            int x = q.front().fi;
            int y = q.front().se;
            if (a[mx[u][v].fi][mx[u][v].se] < a[x][y]) {
                mx[u][v] = {x, y};
            }
            q.pop();
            for (int i = 0; i < 4; i++) {
                int xx = x + dx[i];
                int yy = y + dy[i];
                if (inside(xx, yy) && d[xx][yy] == 0 && a[u][v] + L >= a[xx][yy]) {
                    d[xx][yy] = 1;
                    q.push({xx, yy});
                }
            }
        }
    }

    void solve() {
        d.assign(n + 1, vector<vector<vector<bool>>>(m + 1));
        mx.assign(n + 1, vector<pair<int, int>>(m + 1));
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                d[i][j].assign(n + 1, vector<bool>(m + 1));
                bfs(d[i][j], i, j);
            }
        }
        cin >> q;
        while (q--) {
            int x, y, xx, yy;
            cin >> x >> y >> xx >> yy;
            int ans = 1;
            while (d[x][y][xx][yy] == 0) {
                ans++;
                if (make_pair(x, y) == mx[x][y]) {
                    ans = -1;
                    break;
                }
                int u = mx[x][y].fi, v = mx[x][y].se;
                x = u, y = v;
            }
            cout << ans << "\n";
        }
    }
}

namespace subtask2 {
    vector<vector<int>> ans;
    void process() {
        priority_queue<tuple<int, int, int>, vector<tuple<int, int, int>>, greater<>> pq;
        pq.push({a[1][1], 1, 1});
        int cur = a[1][1];
        int mx = a[1][1];
        int res = 0;
        while (pq.size()) {
            int val, x, y;
            tie(val, x, y) = pq.top();
            pq.pop();
            if (ans[x][y] != inf) continue;
            if (val <= cur + L) {
                ans[x][y] = res;
            }
            else if (val <= mx + L) {
                res++;
                cur = mx;
                ans[x][y] = res;
            }
            else continue;

            mx = max(mx, val);
            for (int i = 0; i < 4; i++) {
                int xx = x + dx[i];
                int yy = y + dy[i];
                if (inside(xx, yy)) {
                    pq.push({a[xx][yy], xx, yy});
                }
            }
        }
    }

    void solve() {
        ans.assign(n + 1, vector<int>(m + 1, inf));
        process();
        cin >> q;
        while (q--) {
            int x, y, xx, yy;
            cin >> x >> y >> xx >> yy;
            if (ans[xx][yy] == inf) {
                ans[xx][yy] = -1;
            }
            else {
                ans[xx][yy]++;
            }
            cout << ans[xx][yy] << "\n";
        }
    }
};

signed main() {
    if (fopen(NAME".INP", "r")) {
        freopen(NAME".INP", "r", stdin);
        freopen(NAME".OUT", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    input();
    if (subtask1::check()) return subtask1::solve(), 0;
    return subtask2::solve(), 0;

    return 0;
}

Compilation message (stderr)

travel.cpp: In function 'int main()':
travel.cpp:147:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  147 |         freopen(NAME".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
travel.cpp:148:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  148 |         freopen(NAME".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 55