Submission #1262769

#	Time	Username	Problem	Language	Result	Execution time	Memory
1262769		tminh	Regions (IOI09_regions)	C++20	0 / 100	313 ms	84856 KiB

regions

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

#define task ""
#define ll long long
#define endl '\n'
#define fi first
#define se second
#define vall(a) (a).begin(), (a).end()
#define sze(a) (int)a.size()
#define pii pair<int, int>
#define pll pair<ll, ll>


#define ep emplace_back
#define pb push_back
#define pf push_front


const ll mod = 1e9 + 7;
const int N = 2e5 + 5;
const ll oo = 1e18;
const int base = 450;

bool START;

int n, r, q, t = 0;
int h[N], p[N], ans[N][450], tin[N], tout[N];
vector<int> arr;
bool nang[N];

vector<int> adj[N], th[N], pos[N];
void euler(int u) {
	tin[u] = ++t;
	th[h[u]].pb(tin[u]);
	pos[h[u]].pb(u);
	for (int v : adj[u]) euler(v);
	tout[u] = t;
}

void dfs(int u, int hxet, int cnt, int id) {
	for (int v : adj[u]) dfs(v, hxet, cnt + (h[u] == hxet), id);
	ans[h[u]][id] += cnt;
}
inline void solve() {
	euler(1);
	for (int i = 1; i <= r; ++i) {
		if (sze(pos[i]) > base) {
			nang[i] = true;
			arr.pb(i);
		}
	}
	for (int i = 0; i < sze(arr); ++i) {
		int hh = arr[i];
		dfs(1, hh, 0, i);
	}
	while(q--) {
		int r1, r2;
		cin >> r1 >> r2;
		if (nang[r1]) {
			int id = lower_bound(vall(arr), r1) - arr.begin();
			cout << ans[r2][id] << endl;
		} else {
			ll ans = 0;
			for (int u : pos[r1]) {
				int in = tin[u], out = tout[u];
				int l = lower_bound(vall(th[r2]), in) - th[r2].begin();
				int r = upper_bound(vall(th[r2]), out) - th[r2].begin();
				ans += (r - l);	
			}
			cout << ans << endl;
		}
	}
}


inline void input() {
    cin >> n >> r >> q;
    cin >> h[1];
    for (int i = 2; i <= n; ++i) {
    	int p; cin >> p >> h[i];
    	adj[p].pb(i);
    }
    return solve();
}
bool END;

int main() {
    if(fopen(task ".inp", "r")) {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    input();
    
    
    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << 's' << endl;
    cerr << "Memory: " << fabs ((&END - &START)) / 1048576.0 << "MB\n";
    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'int main()':
regions.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 85