Submission #731678

#TimeUsernameProblemLanguageResultExecution timeMemory
731678Desh03Regions (IOI09_regions)C++17
30 / 100
4253 ms131072 KiB
#include <bits/stdc++.h>
using namespace std;

unordered_map<short int, int> ans[25000];
vector<int> r[25000], g[200000], euler;
int in[200000], out[200000], fr[25000];
short int c[200000];
int t;
const short int block = 447;

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

void add(int x) {
    fr[euler[x]]++;
}

void remove(int x) {
    fr[euler[x]]--;
}

int main() {
    int n, rr, qq;
    cin >> n >> rr >> qq;
    int x, h;
    cin >> h;
    h--;
    r[h].push_back(0);
    c[0] = h;
    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;
        });
    }
    for (int i = 0; i < rr; i++) {
        int lb, rb;
        if (r[i].size()) lb = in[r[i][0]] + 1, rb = lb - 1;
        for (int u : r[i]) {
            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--);
            for (int j = 0; j < rr; j++)
                if (abs(i - j) <= 5000 && fr[j]) ans[i][j] += fr[j];
        }
        if (r[i].size()) for (int j = 0; j < rr; j++) fr[j] = 0;
    }
    while (qq--) {
        int a, b;
        cin >> a >> b;
        cout << ans[--a][--b] << endl;
    }
}
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