Submission #1283594

#	Time	Username	Problem	Language	Result	Execution time	Memory
1283594		lastgirl	Tourism (JOI23_tourism)	C++20	100 / 100	4456 ms	34532 KiB

tourism

#include <bits/stdc++.h>
// User: Kazuki_Will_Win_VOI_8703
using namespace std;
#define fi first
#define se second
#define pii pair<int, int>
#define ll long long
#define all(a) a.begin(), a.end()

const int mn = 2e5 + 5, lg = 20, inf = 1e5 + 5, mod = 1000000007, B = 320;

int n, m, q, on[mn], up[mn][lg], heavy[mn], d[mn], st[mn], ft[mn], euler[mn], timer_dfs = 0, ans[mn], lg2[mn];
vector <int> a[mn];

void pre_dfs(int u, int p){
    st[u] = ++ timer_dfs;
    d[u] = d[p] + 1;
    euler[timer_dfs] = u;
    for(auto v : a[u]){
        if(v == p) continue;
        pre_dfs(v, u);
        euler[++ timer_dfs] = u;
    }
    ft[u] = timer_dfs;
}

int higher(int u, int v){
    if(d[u] < d[v]) return u;
    return v;
}

void build(){
    for(int i = 1; i <= timer_dfs; i++) up[i][0] = euler[i];
    for(int j = 1; j <= 17; j++){
        for(int i = 1; i + (1 << j) <= timer_dfs; i++){
            up[i][j] = higher(up[i][j - 1], up[i + (1 << (j - 1))][j - 1]);
        }
    }
    lg2[0] = -1;
    for(int i = 1; i <= timer_dfs; i++) lg2[i] = lg2[i / 2] + 1;
}

int lca(int u, int v){
    if(st[u] > st[v]) swap(u, v);
    int l = st[u], r = st[v], j = lg2[r - l + 1];
    return higher(up[l][j], up[r - (1 << j) + 1][j]);
}

int kc(int u, int v){
    int p = lca(u, v);
    return d[u] + d[v] - 2 * d[p];
}

int cur = 0, freq[mn], bit[mn];

void add(int i, int v) {
    for (; i <= timer_dfs; i += i & -i) bit[i] += v;
}

int get(int i) {
    int s = 0;
    for (; i > 0; i -= i & -i) s += bit[i];
    return s;
}

int get_k(int k) {
    int pos = 0, curr = 0;
    for (int d = 1 << 21; d > 0; d >>= 1) {
        if (pos + d <= timer_dfs && curr + bit[pos + d] < k) {
            pos += d;
            curr += bit[pos];
        }
    }
    return pos + 1;
}


void add(int i){
    int u = on[i];
    freq[u] ++;
    if(freq[u] == 1){
        add(st[u], +1);
        int cnt = get(timer_dfs);
        int k = get(st[u]);
        int prev_k = (k == 1 ? cnt : k - 1);
        int next_k = (k == cnt ? 1   : k + 1);
        int u_prev = euler[ get_k(prev_k) ];
        int u_next = euler[ get_k(next_k) ];
        cur -= kc(u_prev, u_next);
        cur += kc(u_prev, u) + kc(u, u_next);
    }
}

void del(int i){
    int u = on[i];
    freq[u] --;
    if(freq[u] == 0){
        int cnt = get(timer_dfs);
        int k = get(st[u]);
        int prev_k = (k == 1 ? cnt : k - 1);
        int next_k = (k == cnt ? 1 : k + 1);
        int u_prev = euler[get_k(prev_k)];
        int u_next = euler[get_k(next_k)];
        cur += kc(u_prev, u_next);
        cur -= kc(u_prev, u) + kc(u, u_next);
        add(st[u], -1);
    }
}

struct Megumi{
    int l, r, id;

    bool operator< (const Megumi& other) const {
        if(l / B == other.l / B) {
            if((l / B) & 1) return r < other.r;
            return r > other.r;
        }
        return l < other.l;
    }
} e[mn];

void solve(){
    cin >> n >> m >> q;
    for(int i = 1; i < n; i++){
        int u, v; cin >> u >> v;
        a[u].push_back(v);
        a[v].push_back(u);
    }
    pre_dfs(1, 0);
    build();
    for(int i = 1; i <= m; i++) cin >> on[i];

    for(int i = 1; i <= q; i++){
        cin >> e[i].l >> e[i].r;
        e[i].id = i;
    }

    sort(e + 1, e + q + 1);
    int ptrl = e[1].l, ptrr = e[1].r;

    for(int i = e[1].l; i <= e[1].r; i++){
        add(i);
    }
    // cerr << cur << '\n';
    ans[e[1].id] = cur / 2;

    for(int i = 2; i <= q; i++){
        while(ptrl < e[i].l) del(ptrl ++);
        while(ptrl > e[i].l) add(-- ptrl);
        while(ptrr < e[i].r) add(++ ptrr);
        while(ptrr > e[i].r) del(ptrr --);
        ans[e[i].id] = cur / 2;
        // cerr << e[i].id << ' ' << ans[e[i].id] << '\n';
    }

    for(int i = 1; i <= q; i++) cout << ans[i] + 1 << '\n';
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen(".inp", "r")) {
        freopen(".inp", "r", stdin);
        freopen(".out", "w", stdout);
    }
    int t = 1;
    // cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

tourism.cpp: In function 'int main()':
tourism.cpp:163:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  163 |         freopen(".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
tourism.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |         freopen(".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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