Submission #1359108

#	Time	Username	Problem	Language	Result	Execution time	Memory
1359108		retarde	Tourism (JOI23_tourism)	C++20	28 / 100	5093 ms	29184 KiB

tourism

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

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

const int mxn = 1e5 + 5;
vi adj[mxn]; int tin[mxn], tout[mxn], dep[mxn], c[mxn], up[mxn][20];

int timer = -1;
void dfs(int node, int prev, int dp) {
    tin[node] = ++timer;
    dep[node] = dp;
    up[node][0] = prev;
    for (auto &neighbour : adj[node]) {
        if (neighbour == prev) continue;
        dfs(neighbour, node, dp + 1);
    }
    tout[node] = timer;
}

int lca(int u, int v) {
    if (dep[u] < dep[v]) swap(u, v);
    if (tin[v] <= tin[u] && tout[u] <= tout[v]) return v;
    for (int k = 19; k >= 0; k--) {
        if (!up[u][k]) continue;
        if (dep[up[u][k]] >= dep[v]) u = up[u][k];
    }
    for (int k = 19; k >= 0; k--) {
        if (up[u][k] == up[v][k]) continue;
        u = up[u][k]; v = up[v][k];
    }
    return up[u][0];
}

int dist(int u, int v) { return dep[u] + dep[v] - 2 * dep[lca(u, v)]; }
inline void solve() {
    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 0; i < n - 1; i++) {
        int u, v; cin >> u >> v;
        adj[u].pb(v); adj[v].pb(u);
    }
    dfs(1, 0, 0);
    for (int k = 1; k < 20; k++) {
        for (int i = 1; i <= n; i++) {
            up[i][k] = up[up[i][k - 1]][k - 1];
        }
    }
    for (int i = 0; i < m; i++) cin >> c[i];

    while (q--) {
        int l, r; cin >> l >> r; l--; r--;
        set<pii> act; act.insert({tin[c[l]], c[l]});
        int ans = 0;
        for (int i = l + 1; i <= r; i++) {
            pii cur = mp(tin[c[i]], c[i]);
            if (act.find(cur) != act.end()) continue;
            act.insert(cur);
            auto it1 = act.lower_bound(cur);
            auto it0 = it1; it0--;
            auto it2 = it1; it2++;
            if (it1 == act.begin()) {
                it0 = act.end();
                it0--;
            }
            if (it2 == act.end()) {
                it2 = act.begin();
            }
            int prev = (*it0).se; int next = (*it2).se; int curn = cur.se;
            ans -= dist(prev, next);
            ans += dist(prev, curn) + dist(curn, next);
        }
        cout << ans/2 + 1 << '\n';
    }
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

tourism.cpp: In function 'void setIO(std::string)':
tourism.cpp:105:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tourism.cpp:106:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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