Submission #1111030

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111030		Neco_arc	Tourism (JOI23_tourism)	C++17	100 / 100	312 ms	23112 KiB

tourism

#include <bits/stdc++.h>

#define ll long long
#define name "Tourism"
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define all(x) x.begin(), x.end()
#define fi(i, a, b)  for(int i = a; i <= b; ++i)
#define fid(i, a, b) for(int i = a; i <= b; --i)
#define maxn (int) (1e5 + 7)

using namespace std;

int n, m, q, Time;
int a[maxn], ans[maxn];
int In[maxn], nex[maxn], siz[maxn], h[maxn], par[maxn];
vector<int> edges[maxn];
struct dl { int l, r, id; } qr[maxn];

struct BIT {
    int bit[maxn];

    void update(int x, int val) {
        for(; x > 0; x -= (x & -x)) bit[x] += val;
    }

    int get(int x, int ans = 0) {
        for(; x < maxn; x += (x & -x)) ans += bit[x];
        return ans;
    }

} Bit;

struct IT {
    int st[4 * maxn];

    int cb(int x, int y) { return x == y ? x : -1; }
    void down(int id) {
        if(st[id] != -1) st[id * 2] = st[id * 2 + 1] = st[id];
    }

    void update(int u, int v, int val, int id = 1, int l = 1, int r = n) {
        if(l > v || r < u) return;
        if(u <= l && r <= v && st[id] != -1) {
            Bit.update(st[id], -(r - l + 1));
            Bit.update(val, r - l + 1), st[id] = val;

            return;
        }

        down(id);
        int mid = (l + r) >> 1;
        update(u, v, val, _left), update(u, v, val, _right);

        st[id] = cb(st[id * 2], st[id * 2 + 1]);
    }

} St;

int dfs_siz(int u) {
    siz[u] = 1;
    for(int &v : edges[u]) {
        edges[v].erase(find(all(edges[v]), u));
        siz[u] += dfs_siz(v);

        if(siz[v] > siz[edges[u][0]]) swap(v, edges[u][0]);
    }
    return siz[u];
}

void dfs_hld(int u) {
    In[u] = ++Time;
    for(int v : edges[u]) {
        par[v] = u, h[v] = h[u] + 1;
        nex[v] = v == edges[u][0] ? nex[u] : v;

        dfs_hld(v);
    }
}

void update(int u, int v, int val) {
    for(; nex[u] != nex[v]; u = par[nex[u]]) {
        if(h[nex[u]] < h[nex[v]]) swap(u, v);
        St.update(In[nex[u]], In[u], val);
    }
    if(h[u] < h[v]) swap(u, v);
    St.update(In[v], In[u], val);
}

int Query(int x) {
    int ans = Bit.get(x);
    return ans == 0 ? 1 : ans;
}

void solve() {

    cin >> n >> m >> q;
    fi(i, 1, n - 1) {
        int x, y; cin >> x >> y;
        edges[x].push_back(y), edges[y].push_back(x);
    }
    fi(i, 1, m) cin >> a[i];
    fi(i, 1, q) {
        int l, r, id = i; cin >> l >> r;
        qr[i] = {l, r, id};
    }

    nex[1] = 1;
    dfs_siz(1), dfs_hld(1);

    int j = 1;
    sort(qr + 1, qr + 1 + q, [](dl x, dl y) { return x.r < y.r; });

    fi(i, 1, q) {
        while(j < qr[i].r) {
            ++j;
            if(j > 1) update(a[j - 1], a[j], j - 1);
        }
        ans[qr[i].id] = Query(qr[i].l);
    }

    fi(i, 1, q) cout << ans[i] << '\n';


}

int main() {

    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    if(fopen(name".inp", "r")) {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }

    solve();

}

Compilation message (stderr)

tourism.cpp: In function 'int main()':
tourism.cpp:133:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  133 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tourism.cpp:134:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |         freopen(name".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