Submission #854278

#	Time	Username	Problem	Language	Result	Execution time	Memory
854278		Lobo	Through Another Maze Darkly (CCO21_day1problem3)	C++17	0 / 25	366 ms	1048580 KiB

Main

#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
// #define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 8e5+10;
const int lg = 60;

int n, q, q0, rt[2*maxn], pt[maxn];
vector<int> g[maxn];
map<int,int> id[maxn];
vector<pair<int,int>> dp[lg+1][maxn];
void solve() {
    cin >> n >> q;

    q0 = 2*n;

    for(int i = 1; i <= n; i++) {
        int cnt; cin >> cnt;

        for(int j = 0; j < cnt; j++) {
            int v; cin >> v;
            g[i].pb(v);
        }
        pt[i] = 0;

    }

    rt[0] = 1;
    for(int i = 1; i <= q0; i++) {
        pt[rt[i-1]] = (pt[rt[i-1]]+1)%g[rt[i-1]].size();
        rt[i] = g[rt[i-1]][pt[rt[i-1]]];
    }


    for(int i = 1; i <= n; i++) {
        int cnt = g[i].size();

        vector<int> newg;
        for(int j = pt[i]; j < g[i].size(); j++) newg.pb(g[i][j]);
        for(int j = 0; j < pt[i]; j++) newg.pb(g[i][j]);
        g[i] = newg;

        for(int j = 0; j < cnt; j++) {
            int v = g[i][j];
            id[i][v] = j;
        }

        for(int j = 0; j < cnt; j++) {
            // cout << j << " " << (j+1)%cnt << " " << g[i].size() << " " << g[i][(j+1)%cnt] << endl;
            dp[0][i].pb(mp(g[i][(j+1)%cnt],i));
        }
    }
    for(int b = 1; b <= lg; b++) {
        for(int u = 1; u <= n; u++) {
            for(int i = 0; i < g[u].size(); i++) {
                int v = g[u][i];
                auto aux = dp[b-1][u][i];
                int u1 = aux.fr;
                int v1 = aux.sc;

                dp[b][u].pb(dp[b-1][u1][id[u1][v1]]);
            }
        }
    }


    while(q--) {
        int k; cin >> k;

        if(k <= q0) {
            cout << rt[k] << endl;
            continue;
        }

        int u = 1;
        int v = g[u][0];
        for(int b = 0; b <= lg; b++) {
            if((1LL<<b)&k) {
                auto aux = dp[b][u][id[u][v]];
                u = aux.fr;
                v = aux.sc;
            }
        }

        cout << u << endl;
    }


}
    
int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:47:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         for(int j = pt[i]; j < g[i].size(); j++) newg.pb(g[i][j]);
      |                            ~~^~~~~~~~~~~~~
Main.cpp:63:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |             for(int i = 0; i < g[u].size(); i++) {
      |                            ~~^~~~~~~~~~~~~
Main.cpp:64:21: warning: unused variable 'v' [-Wunused-variable]
   64 |                 int v = g[u][i];
      |                     ^

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