Submission #390186

#	Time	Username	Problem	Language	Result	Execution time	Memory
390186		arwaeystoamneg	Regions (IOI09_regions)	C++17	100 / 100	4587 ms	54944 KiB

regions

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
//#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
}

const int MAX = 2e5 + 3, MAXK = 25e3 + 5;
vi adj[MAX], c[MAXK], d[MAXK];
int n, k, q, a[MAX], sizes[MAX], po = 0, tin[MAX], timenow;
void dfs(int i, int p = -1)
{
	c[a[i]].pb(i);
	tin[i] = timenow++;
	sizes[i] = 1;
	trav(x, adj[i])
	{
		if (x == p)continue;
		dfs(x, i);
		sizes[i] += sizes[x];
	}
}
map<int, int>ans[MAXK];
vi dp[MAXK];
void dfs(int i, int p, int t)
{
	if (a[i] == t)dp[t][i]++;
	trav(x, adj[i])
	{
		if (x == p)continue;
		dp[t][x] += dp[t][i];
		dfs(x, i, t);
	}
}
int main()
{
	setIO("");
	cin >> n >> k >> q;
	cin >> a[0];
	a[0]--;
	FOR(i, 1, n)
	{
		int p;
		cin >> p;
		adj[i].pb(--p);
		adj[p].pb(i);
		cin >> a[i];
		a[i]--;
	}
	dfs(0);
	int sq = 700;
	F0R(i, k)
	{
		trav(x, c[i])d[i].pb(tin[x]);
	}
	F0R(i, k)
	{
		if (sz(c[i]) > sq)
		{
			dp[i].rsz(n);
			dfs(0, -1, i);
		}
	}
	while (q--)
	{
		int x, y;
		cin >> x >> y;
		x--, y--;
		if (ans[x].find(y) != ans[x].end())
		{
			cout << ans[x][y] << endl;
		}
		else if (sz(c[y]) < sq && sz(c[x]) > sq)
		{
			int res = 0;
			trav(t, c[y])
			{
				res += dp[x][t];
			}
			ans[x][y] = res;
			cout << res << endl;
		}
		else
		{
			int res = 0;
			trav(t, c[x])
			{
				res += upper_bound(all(d[y]), tin[t] + sizes[t] - 1) - lower_bound(all(d[y]), tin[t]);
			}
			ans[x][y] = res;
			cout << res << endl;
		}
	}

}

Compilation message (stderr)

regions.cpp: In function 'void setIO(std::string)':
regions.cpp:48:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   48 |   freopen((s + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:50:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   50 |    freopen((s + ".out").c_str(), "w", stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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