Submission #1026965

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026965		daisy2	Regions (IOI09_regions)	C++17	65 / 100	8063 ms	131072 KiB

regions

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

int n, chair, q, tim = 0, in[200005], out[200005], rper[200005], reg, a, b;
vector<int> v[200005], perr[200005];
map<int, int> dp[25000];
multiset<int> d[500005];

void dfs(int vr) {
    tim++;
    in[vr] = tim;
    d[rper[vr]].insert(in[vr]);

    for (int i = 0; i < v[vr].size(); i++)
        dfs(v[vr][i]);

    out[vr] = tim;
}

void dfs2(int vr, int cntim, int curr) {
    if (rper[vr] == curr) cntim++;
    else dp[curr][rper[vr]] += cntim;

    for (int i = 0; i < v[vr].size(); i++)
        dfs2(v[vr][i], cntim, curr);
}

int main() {
    cin >> n >> reg >> q;
    cin >> chair;

    rper[1] = chair;
    perr[chair].push_back(1);

    int sup, regper;
    for (int i = 2; i <= n; i++) {
        cin >> sup >> regper;
        v[sup].push_back(i);
        rper[i] = regper;
        perr[regper].push_back(i);
    }
    dfs(1);
    int k = sqrt(n);

    for (int i = 1; i <= reg; i++) {
        if (d[i].size() >= k) {
            dfs2(1, 0, i);
        }
    }
    while (q--) {
        cin >> a >> b;
        if (d[a].size() >= k) {
            cout << dp[a][b] << endl;
        } else {
            int res = 0;
            for (int i = 0; i < perr[a].size(); i++) {
                res += distance(d[b].lower_bound(in[perr[a][i]]), d[b].upper_bound(out[perr[a][i]]));
            }
            cout << res << endl;
        }
        cout.flush();
    }
}

Compilation message (stderr)

regions.cpp: In function 'void dfs(int)':
regions.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for (int i = 0; i < v[vr].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
regions.cpp: In function 'void dfs2(int, int, int)':
regions.cpp:27:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     for (int i = 0; i < v[vr].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
regions.cpp: In function 'int main()':
regions.cpp:49:25: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |         if (d[i].size() >= k) {
      |             ~~~~~~~~~~~~^~~~
regions.cpp:55:25: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   55 |         if (d[a].size() >= k) {
      |             ~~~~~~~~~~~~^~~~
regions.cpp:59:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             for (int i = 0; i < perr[a].size(); i++) {
      |                             ~~^~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 50 / 85