Submission #889618

#	Time	Username	Problem	Language	Result	Execution time	Memory
889618		vjudge1	Tourism (JOI23_tourism)	C++17	10 / 100	5083 ms	8552 KiB

tourism

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m, q; cin >> n >> m >> q;
    vector <vector<int>> G(n);
    for ( int i = 1; i < n; i++ ){
        int u, v; cin >> u >> v;
        --u, --v;
        G[u].pb(v), G[v].pb(u);
    }
    vector <int> C(m);
    for ( auto &x: C ){
        cin >> x; --x;
    }
    while ( q-- ){
        int l, r; cin >> l >> r;
        --l, --r;
        int s = r - l + 1;
        vector <int> sub(n), hv(n);
        for ( int i = l; i <= r; i++ ){
            sub[C[i]]++;
            hv[C[i]] = true;
        }
        auto dfs = [&](auto dfs, int u, int p) -> void{
            for ( auto &v: G[u] ){
                if ( v != p ){
                    dfs(dfs, v, u);
                    sub[u] += sub[v];
                }
            }
        };
        dfs(dfs, 0, -1);
        int ans = 0;
        auto dfs2 = [&](auto dfs2, int u, int p) -> void{
            bool flag = false, vs = false;
            for ( auto &v: G[u] ){
                if ( sub[v] ){
                    if ( !vs ) vs = true;
                    else flag = true;
                }
            }
            if ( hv[u] || flag ) ++ans;
            for ( auto &v: G[u] ){
                if ( v != p ){
                    sub[u] -= sub[v];
                    sub[v] += sub[u];
                    dfs2(dfs2, v, u);
                    sub[v] -= sub[u];
                    sub[u] += sub[v];
                }
            }
        };
        dfs2(dfs2, 0, -1);
        cout << ans << ln;
    }

    cout << '\n';
}

Compilation message (stderr)

tourism.cpp: In function 'int main()':
tourism.cpp:49:13: warning: unused variable 's' [-Wunused-variable]
   49 |         int s = r - l + 1;
      |             ^

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 41