Submission #918884

#	Time	Username	Problem	Language	Result	Execution time	Memory
918884		ShaShi	Regions (IOI09_regions)	C++17	100 / 100	3633 ms	105148 KiB

regions

#include <bits/stdc++.h>
// #define int long long 
#define F first
#define S second
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define kill(x) cout << x << endl, exit(0);
#define mp make_pair
#define pb push_back
// #define endl "\n"
 
 
using namespace std;
typedef long long ll;
 
const int MAXN = (int)2e5 + 7;
const int MOD = 999999893;
const int INF = (int)1e9 + 7;
const int SQ = 450;

 
int n, m, t, flag, u, v, w, k, tmp, tmp2, tmp3, tmp4, tmp5, tmp6, ans, q, ans2;
int arr[MAXN], num[MAXN], id[MAXN], st[MAXN], ft[MAXN];
int res[SQ][MAXN];
vector<int> adj[MAXN], col[MAXN], vec[MAXN];


void DFSsz(int v) {
    st[v] = flag; vec[arr[v]].pb(flag++);

    for (int u:adj[v]) DFSsz(u);

    ft[v] = flag;
}


void DFS(int v, int x, int id, int bala) {
    res[id][arr[v]] += bala; bala += (arr[v] == x);

    for (int u:adj[v]) DFS(u, x, id, bala);
}


int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); 

    cin >> n >> m >> q;

    cin >> arr[1];
    col[arr[1]].pb(1); num[arr[1]]++;

    for (int i=2; i<=n; i++) {
        cin >> u >> arr[i];
        adj[u].pb(i); col[arr[i]].pb(i); num[arr[i]]++;
    }

    DFSsz(1); flag = 0;

    for (int i=1; i<=m; i++) {
        if (num[i] >= SQ) {
            id[i] = flag;
            DFS(1, i, flag, 0); 
            flag++;
        }
    }

    for (int i=1; i<=m; i++) vec[i].pb(INF);

    while (q--) {
        cin >> u >> v;

        // cout << "!";

        if (num[u] < SQ) {
            ans = 0;

            for (int w:col[u]) ans += lower_bound(all(vec[v]), ft[w])-lower_bound(all(vec[v]), st[w]);
      
            cout << ans << endl;
        } else {
            cout << res[id[u]][v] << endl;
        }
    }


    return 0;
}

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