Submission #576325

#	Time	Username	Problem	Language	Result	Execution time	Memory
576325		eecs	Through Another Maze Darkly (CCO21_day1problem3)	C++17	0 / 25	9049 ms	24512 KiB

Main

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

typedef long long ll;
const int maxn = 800010;
int n, q, ptr[maxn], fa[maxn];
bool vis[maxn];
vector<int> G[maxn];

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> q;
    for (int i = 1, k; i <= n; i++) {
        cin >> k;
        while (k--) {
            int c;
            cin >> c, G[i].push_back(c);
        }
    }
    auto dfs = [&](auto self, int u) -> void {
        for (int v : G[u]) if (v ^ fa[u]) {
            fa[v] = u, self(self, v);
        }
    };
    dfs(dfs, 1);
    while (q--) {
        ll k;
        cin >> k;
        fill(ptr + 1, ptr + n + 1, 0);
        fill(vis + 1, vis + n + 1, 0);
        int u = 1, cnt = 0;
        do {
            if (!vis[u]) vis[u] = 1, cnt++;
            u = G[u][++ptr[u] %= G[u].size()];
        } while (--k && cnt < n);
        if (!k) { cout << u << "\n"; continue; }
        k %= 2 * n - 2;
        while (k--) u = G[u][++ptr[u] %= G[u].size()];
        cout << u << "\n";
    }
    return 0;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 4
• Subtask 3: 0 / 12
• Subtask 4: 0 / 5