Submission #511360

#	Time	Username	Problem	Language	Result	Execution time	Memory
511360		tabr	Tropical Garden (IOI11_garden)	C++17	100 / 100	2569 ms	23404 KiB

garden

#include <bits/stdc++.h>
using namespace std;
#ifdef tabr
#include "library/debug.cpp"
#else
#define debug(...)
#endif

#ifdef tabr
void answer(int n) {
    cout << n << '\n';
}
#else
#include "garden.h"
#include "gardenlib.h"
#endif

void count_routes(int n, int m, int p, int r[][2], int q, int k[]) {
    vector<vector<int>> g(n);
    for (int i = 0; i < m; i++) {
        g[r[i][0]].emplace_back(r[i][1]);
        g[r[i][1]].emplace_back(r[i][0]);
    }
    vector<int> nxt(2 * n);
    for (int i = 0; i < n; i++) {
        nxt[i] = g[i][0];
        nxt[i + n] = (g[i].size() == 1 ? g[i][0] : g[i][1]);
        if (g[nxt[i]][0] == i) {
            nxt[i] += n;
        }
        if (g[nxt[i + n]][0] == i) {
            nxt[i + n] += n;
        }
    }
    g = vector<vector<int>>(2 * n);
    for (int i = 0; i < 2 * n; i++) {
        g[nxt[i]].emplace_back(i);
    }
    vector<int> a(2 * n, -1), b(2 * n, -1);
    a[p] = 0;
    b[p + n] = 0;
    queue<int> que;
    que.emplace(p);
    while (!que.empty()) {
        int v = que.front();
        que.pop();
        for (int to : g[v]) {
            if (a[to] == -1) {
                a[to] = a[v] + 1;
                que.emplace(to);
            }
        }
    }
    que.emplace(p + n);
    while (!que.empty()) {
        int v = que.front();
        que.pop();
        for (int to : g[v]) {
            if (b[to] == -1) {
                b[to] = b[v] + 1;
                que.emplace(to);
            }
        }
    }
    int c = 0;
    int v = p;
    do {
        v = nxt[v];
        c++;
    } while (v != p && c < 2 * n + 1);
    int d = 0;
    v = p + n;
    do {
        v = nxt[v];
        d++;
    } while (v != p + n && d < 2 * n + 1);
    debug(c, d);
    for (int i = 0; i < q; i++) {
        int ans = 0;
        for (int j = 0; j < n; j++) {
            if (c > 2 * n) {
                if (k[i] == a[j]) {
                    ans++;
                }
            } else {
                if (a[j] != -1 && k[i] >= a[j] && (k[i] - a[j]) % c == 0) {
                    ans++;
                }
            }
            if (d > 2 * n) {
                if (k[i] == b[j]) {
                    ans++;
                }
            } else {
                if (b[j] != -1 && k[i] >= b[j] && (k[i] - b[j]) % d == 0) {
                    ans++;
                }
            }
        }
        answer(ans);
    }
}

#ifdef tabr
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m, p, q;
    cin >> n >> m >> p >> q;
    int r[100][2];
    int k[100];
    for (int i = 0; i < m; i++) {
        cin >> r[i][0] >> r[i][1];
    }
    for (int i = 0; i < q; i++) {
        cin >> k[i];
    }
    count_routes(n, m, p, r, q, k);
    return 0;
}
#endif

• Subtask 1: 49 / 49
• Subtask 2: 20 / 20
• Subtask 3: 31 / 31