Submission #1255349

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255349		spampots	Regions (IOI09_regions)	C++17	85 / 100	8069 ms	29696 KiB

regions

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

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;

const int MOD = 1e9 + 7;
const int INF = INT_MAX;
const ll LINF = LLONG_MAX;

#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define rep(i, a, b) for(int i = a; i < b; ++i)

void solve() {
    int n, r, q;
    cin >> n >> r >> q;

    vector<vector<int>> adj(n);
    vector<vector<int>> c(r);
    vector<int> reg(n);

    cin >> reg[0];
    reg[0]--;
    c[reg[0]].pb(0);
    for(int i = 1; i < n; i++){
        int sk;
        cin >> sk >> reg[i];
        sk--;
        reg[i]--;
        adj[sk].pb(i);
        c[reg[i]].pb(i);
    }

    int timer = 0;
    vector<int> tIn(n), tOut(n);

    function<void(int)> dfs = [&](int node) {
        tIn[node] = timer++;
        for(int x : adj[node])
            dfs(x);
        tOut[node] = timer;
    };

    dfs(0);

    vector<vector<int>> comp(r);

    for(int i = 0; i < n; ++i)
        comp[reg[i]].pb(tIn[i]);

    for(int i = 0; i < r; ++i)
        sort(all(comp[i]));

    for(int i = 0; i < q; ++i) {
        int r1, r2;
        cin >> r1 >> r2;
        r1--, r2--;
        int ans = 0;
        for(int x : c[r1]) {
            int l = tIn[x], r = tOut[x]-1;
            ans += upper_bound(all(comp[r2]), r) - lower_bound(all(comp[r2]), l);
        }
        cout << ans << endl;
    }
}

int main() {
    fast;

    int t = 1;
    while(t--) {
        solve();
    }

    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 70 / 85