Submission #1213506

#	Time	Username	Problem	Language	Result	Execution time	Memory
1213506		vanea	Regions (IOI09_regions)	C++20	35 / 100	8093 ms	26820 KiB

regions

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

const int mxN = 2e5+10;
const int mxR = 3e4+10;

int reg[mxN], st[4*mxN];
vector<int> adj[mxN], emp[mxR];
int tin[mxN], tout[mxN], timer = -1;

void dfs(int node, int p) {
    tin[node] = ++timer;
    for(auto it : adj[node]) {
        if(it == p) continue;
        dfs(it, node);
    }
    tout[node] = timer;
}

void upd(int node, int l, int r, int k, int x) {
    if(l == r && l == k) {
        st[node] = x;
        return ;
    }
    if(l > k || r < k) return ;
    int mid = (l+r)/2;
    upd(node*2, l, mid, k, x);
    upd(node*2+1, mid+1, r, k, x);
    st[node] = st[node*2] + st[node*2+1];
}

int qry(int node, int l, int r, int l1, int r1) {
    if(l1 <= l && r <= r1) return st[node];
    if(l1 > r || r1 < l) return 0;
    int mid = (l+r)/2;
    return qry(node*2, l, mid, l1, r1) + qry(node*2+1, mid+1, r, l1, r1);
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, r, q;
    cin >> n >> r >> q;
    cin >> reg[1];
    emp[reg[1]].push_back(1);
    for(int i = 2; i <= n; i++) {
        int p;
        cin >> p >> reg[i];
        emp[reg[i]].push_back(i);
        adj[p].push_back(i);
        adj[i].push_back(p);
    }
    dfs(1, 0);
    while(q--) {
        int r1, r2;
        cin >> r1 >> r2;
        int ans = 0;
        for(auto it : emp[r2]) {
            upd(1, 0, timer+1, tin[it], 1);
        }
        for(auto it : emp[r1]) {
            ans += qry(1, 0, timer+1, tin[it], tout[it]);
        }
        for(auto it : emp[r2]) {
            upd(1, 0, timer+1, tin[it], 0);
        }
        cout << ans << '\n';
        cout.flush();
    }
    return 0;
}

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