Submission #307446

#	Time	Username	Problem	Language	Result	Execution time	Memory
307446		syy	Stations (IOI20_stations)	C++17	100 / 100	1012 ms	1288 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define FOR(i, a, b) for(int i = (int)a; i <= (int)b; i++)
#define DEC(i, a, b) for(int i = (int)a; i >= (int)b; i--)
typedef pair<int, int> pi;
typedef pair<pi, int> pii;
typedef pair<pi, pi> pipi;
#define f first
#define s second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<pii> vpii;
#define pb push_back
#define pf push_front
#define all(v) v.begin(), v.end()
#define disc(v) sort(all(v)); v.resize(unique(all(v)) - v.begin());
#define INF (int) 1e9 + 100
#define LLINF (ll) 1e18
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define sandybridge __attribute__((optimize("Ofast"), target("arch=sandybridge")))
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline ll rand(ll x, ll y) { ++y; return (rng() % (y-x)) + x; } //inclusivesss

int n, coun;
vi adj[1005], res;

// counting from 0
// Even row: smaller that all in subtree
// Odd row: greater than all in subtree
void dfs(int x, int p, bool dep) {
	if (!dep) res[x] = coun++;
	for (auto it:adj[x]) if (it != p) dfs(it, x, !dep);
	if (dep) res[x] = coun++;
}

vector<int> label(int N, int k, vector<int> u, vector<int> v) {
	n = N; res.clear(); res.resize(n);
	FOR(i, 0, n-1) adj[i].clear();
	coun = 0;
	FOR(i, 0, n-2) adj[u[i]].pb(v[i]), adj[v[i]].pb(u[i]);
	int st = 0; FOR(i, 0, n-1) if (adj[i].size() == 1) st = i;
	dfs(st, -1, 0);
	return res;
}

int find_next_station(int s, int t, vector<int> c) {
	if (s < c[0]) { // Even row
		if (t < s or t >= c.back()) return c.back(); // must be out of subtree
		return *lower_bound(all(c), t); // lower_bound so children has space to "reduce" down to t
	} else { // Odd row
		if (t > s or t <= c[0]) return c[0]; // must be out of subtree
		return *(--upper_bound(all(c), t)); // upper_bound so children has space to "increase" up to t
	}
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61