Submission #731616

#	Time	Username	Problem	Language	Result	Execution time	Memory
731616		Desh03	Regions (IOI09_regions)	C++17	34 / 100	8090 ms	131072 KiB

regions

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

vector<vector<int>> r, g;
vector<int> euler, in, out, fr, c;
int t, cnt, b;
const int block = 447;

void dfs(int u) {
    in[u] = t++;
    euler.push_back(u);
    for (int v : g[u])
        dfs(v);
    out[u] = t - 1;
}

void add(int x) {
    cnt += c[euler[x]] == b;
}

void remove(int x) {
    cnt -= c[euler[x]] == b;
}

int main() {
    int n, rr, qq;
    cin >> n >> rr >> qq;
    g.resize(n), r.resize(rr), in.resize(n), out.resize(n), fr.resize(rr), c.resize(n);
    int x, h;
    cin >> h;
    h--;
    r[h].push_back(0);
    c[0] = h;
    map<int, map<int, int>> mp;
    map<pair<int, int>, int> mp2;
    for (int i = 1; i < n; i++) {
        cin >> x >> h;
        x--, h--;
        r[h].push_back(i);
        g[x].push_back(i);
        c[i] = h;
    }
    dfs(0);
    for (int i = 0; i < rr; i++) {
        sort(r[i].begin(), r[i].end(), [](const int &a, const int &b) {
             int a1 = in[a] / block, b1 = in[b] / block;
             return a1 == b1 ? out[a] < out[b] : a1 < b1;
        });
    }
    while (qq--) {
        int a, ans = 0;
        cin >> a >> b;
        a--, b--, cnt = 0;
        if (mp2.find({a, b}) != mp2.end()) {
            cout << mp2[{a, b}] << '\n';
            continue;
        }
        int lb, rb;
        if (r[a].size()) lb = in[r[a][0]] + 1, rb = lb - 1;
        for (int u : r[a]) {
            if (mp[u].find(b) != mp[u].end()) cnt += mp[u][b];
            else {
                int l_ = in[u] + 1, r_ = out[u];
                while (lb > l_) add(--lb);
                while (rb < r_) add(++rb);
                while (lb < l_) remove(lb++);
                while (rb > r_) remove(rb--);
                mp[u][b] = cnt;
                ans += cnt;
            }
        }
        cout << ans << endl;
        mp2[{a, b}] = ans;
    }
}

• Subtask 1: 14 / 15
• Subtask 2: 20 / 85