Submission #884150

#	Time	Username	Problem	Language	Result	Execution time	Memory
884150		fanwen	Tourism (JOI23_tourism)	C++17	18 / 100	341 ms	13876 KiB

tourism

#include <bits/stdc++.h>

#define fi first
#define se second
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }

using namespace std;

#ifdef LOCAL
    #include "debug.h"
#else
    #define clog if(false) cerr
#endif

template <class T> struct Fenwick_Tree {
    vector<T> bit;
    int n;
    Fenwick_Tree(int _n = 0) : n(_n), bit(_n + 5){}

    void clear() { fill(bit.begin(), bit.end(), T(0)); }

    void update(int u, T val) {
        for (; u <= n; u += u & -u) bit[u] += val;
    }

    T get(int u) {
        T ans = 0;
        for (; u; u -= u & -u) ans += bit[u];
        return ans;
    }

    T get(int l, int r) {
        return get(r) - get(l - 1);
    }
};


const int MAX = 1e5 + 5;

int n, m, q, c[MAX], ans[MAX], local[MAX], depth[MAX], header[MAX], par[MAX];
int numChild[MAX];
vector <int> adj[MAX];
vector <pair <int, int>> queries[MAX];

void dfs(int u, int p) {
    numChild[u] = 1;
    int Max = 0, id = 0;
    for (int i = 0; i < (int) adj[u].size(); ++i) if(adj[u][i] != p) {
        int v = adj[u][i];
        dfs(v, u);
        numChild[u] += numChild[v];
        if(Max < numChild[v]) {
            Max = numChild[v];
            id = i;
        }
    }
    swap(adj[u][0], adj[u][id]);
}

void dfs_hld(int u, int p) {
    static int run = 0;
    local[u] = ++run;
    par[u] = p;
    for (int i = 0; i < (int) adj[u].size(); ++i) if(adj[u][i] != p) {
        int v = adj[u][i];
        if(i == 0 && numChild[v] * 2 >= numChild[u]) {
            header[v] = header[u], depth[v] = depth[u];
        } else {
            header[v] = v;
            depth[v] = depth[u] + 1;
        }
        dfs_hld(v, u);
    }
}

int it[4 * MAX];

Fenwick_Tree <int> bit;

void pushdown(int idx) {
    if(it[idx] == -1) return;
    it[idx << 1] = it[idx << 1 | 1] = it[idx];
}

void update(int idx, int l, int r, int u, int v, int val) {
    if(l > v || r < u) return;
    if(l >= u && r <= v && it[idx] >= 0) {
        if(it[idx] > 0) bit.update(it[idx], - (r - l + 1));
        bit.update(it[idx] = val, r - l + 1);
        return;
    }

    pushdown(idx);

    int mid = l + r >> 1;
    update(idx << 1, l, mid, u, v, val);
    update(idx << 1 | 1, mid + 1, r, u, v, val);
    it[idx] = (it[idx << 1] == it[idx << 1 | 1] ? it[idx << 1] : -1);
}

void update_hld(int u, int v, int val) {
    while(header[u] != header[v]) {
        if(local[header[u]] < local[header[v]]) swap(u, v);
        update(1, 1, n, local[header[u]], local[u], val);
        u = par[header[u]];
    }
    update(1, 1, n, min(local[u], local[v]), max(local[u], local[v]), val);
}

void you_make_it(void) {
    cin >> n >> m >> q;
    for (int i = 1; i < n; ++i) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 1; i <= m; ++i) cin >> c[i];
    dfs(1, 0); depth[1] = header[1] = 1; dfs_hld(1, 0);

    fill(ans + 1, ans + q + 1, 1);
    for (int i = 1; i <= q; ++i) {
        int l, r; cin >> l >> r;
        if(l < r) queries[l].emplace_back(r, i);
    }

    bit = Fenwick_Tree <int> (m);
    for (int i = m - 1; i >= 1; --i) {
        update_hld(c[i], c[i + 1], i + 1);
        for (auto [r, id] : queries[i]) ans[id] = bit.get(r);
    }
    for (int i = 1; i <= q; ++i) cout << ans[i] << '\n';
}

signed main() {

#ifdef LOCAL
    freopen("TASK.inp", "r", stdin);
    freopen("TASK.out", "w", stdout);
#endif
    file("tourism");
    auto start_time = chrono::steady_clock::now();

    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);

    you_make_it();

    auto end_time = chrono::steady_clock::now();

    cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

// Dream it. Wish it. Do it.

Compilation message (stderr)

tourism.cpp: In function 'void update(int, int, int, int, int, int)':
tourism.cpp:95:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   95 |     int mid = l + r >> 1;
      |               ~~^~~
tourism.cpp: In instantiation of 'Fenwick_Tree<T>::Fenwick_Tree(int) [with T = int]':
tourism.cpp:78:20:   required from here
tourism.cpp:17:9: warning: 'Fenwick_Tree<int>::n' will be initialized after [-Wreorder]
   17 |     int n;
      |         ^
tourism.cpp:16:15: warning:   'std::vector<int> Fenwick_Tree<int>::bit' [-Wreorder]
   16 |     vector<T> bit;
      |               ^~~
tourism.cpp:18:5: warning:   when initialized here [-Wreorder]
   18 |     Fenwick_Tree(int _n = 0) : n(_n), bit(_n + 5){}
      |     ^~~~~~~~~~~~
tourism.cpp: In function 'int main()':
tourism.cpp:5:57: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tourism.cpp:140:5: note: in expansion of macro 'file'
  140 |     file("tourism");
      |     ^~~~
tourism.cpp:5:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
tourism.cpp:140:5: note: in expansion of macro 'file'
  140 |     file("tourism");
      |     ^~~~

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