Submission #1081552

#	Time	Username	Problem	Language	Result	Execution time	Memory
1081552		GrindMachine	Stations (IOI20_stations)	C++17	0 / 100	627 ms	940 KiB

stations

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

typedef long long int ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define pb push_back
#define endl '\n'
#define conts continue
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sz(a) (int)a.size()

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &x, T y){
	x = min(x,y);
}

template<typename T>
void amax(T &x, T y){
	x = max(x,y);
}

template<typename A,typename B>
string to_string(pair<A,B> p);

string to_string(const string &s){
	return "'"+s+"'";
}

string to_string(const char* s){
	return to_string((string)s);
}

string to_string(bool b){
	return b?"true":"false";
}

template<typename A>
string to_string(A v){
	string res = "{";
	trav(x,v){
		res += to_string(x)+",";
	}
	if(res.back() == ',') res.pop_back();
	res += "}";
	return res;
}

template<typename A,typename B>
string to_string(pair<A,B> p){
	return "("+to_string(p.ff)+","+to_string(p.ss)+")";
}

#define debug(x) cout << "[" << #x << "]: "; cout << to_string(x) << endl

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = (ll)1e18 + 5;

#include "stations.h"

std::vector<int> label(int n, int k, std::vector<int> U, std::vector<int> V) {
	vector<vector<int>> adj(n);
	rep(i,n-1){
		int u = U[i], v = V[i];
		adj[u].pb(v), adj[v].pb(u);
	}

	vector<int> tin(n), subsiz(n), dummy(n);
	int timer = 0;

	auto nxt_pow_2 = [&](int x){
		for(int i = 1; ; i <<= 1){
			if(i >= x) return i;
		}
		return 0;
	};

	auto dfs1 = [&](int u, int p, auto &&dfs1) -> void{
		vector<int> sizes;
		subsiz[u] = 1;

		trav(v,adj[u]){
			if(v == p) conts;
			adj[v].erase(find(all(adj[v]),u));
			dfs1(v,u,dfs1);
			sizes.pb(subsiz[v]);
			subsiz[u] += subsiz[v];
		}

		sort(all(sizes));

		if(sz(sizes) > 1){
			int val = subsiz[u]-sizes[0]+sizes[1];
			int new_siz = nxt_pow_2(val);
			dummy[u] = new_siz-subsiz[u];
		}

		subsiz[u] += dummy[u];
	};

	auto cmp = [&](int u, int v){
		return subsiz[u] > subsiz[v];
	};

	auto dfs2 = [&](int u, int p, auto &&dfs2) -> void{
		sort(all(adj[u]),cmp);
		tin[u] = timer++;
		trav(v,adj[u]){
			dfs2(v,u,dfs2);
		}
		timer += dummy[u];
		assert(timer-tin[u] == subsiz[u]);
	};

	dfs1(0,-1,dfs1);
	dfs2(0,-1,dfs2);

	return tin;

	// std::vector<int> labels(n);
	// for (int i = 0; i < n; i++) {
	// 	labels[i] = i;
	// }
	// return labels;
}

int find_next_station(int s, int t, std::vector<int> c) {
	auto nxt_pow_2 = [&](int x){
		for(int i = 1; ; i <<= 1){
			if(i >= x) return i;
		}
		return 0;
	};

	if(sz(c) == 1){
		return c[0];
	}

	if(t < s){
		return c[0];
	}

	if(sz(c) == 2){
		return c[1];
	}

	rep(i,sz(c)-1){
		if(c[i] <= t and t < c[i+1]){
			return c[i];
		}
	}

	int sum = c.back()-s;
	int subsiz = nxt_pow_2(sum);

	if(t < s+subsiz){
		return c.back();
	}
	else{
		return c[0];
	}

	assert(0);
	return -1;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61