Submission #578731

#	Time	Username	Problem	Language	Result	Execution time	Memory
578731		Noam527	Game (APIO22_game)	C++17	100 / 100	1479 ms	69632 KiB

game

#include <bits/stdc++.h>
#include "game.h"
const int OO = 0;
const int OOO = 0;
using namespace std;

int n, k;
vector<vector<int>> g, grev;
vector<int> s, e;
// s: maximum that reaches us
// e: minimum that we can reach
// s <= e as long as the answer is 0 (with s < e for all non-special vertices)

void init(int nn, int kk) {
	g.clear();
	grev.clear();
	s.clear();
	e.clear();

	n = nn;
	k = kk;
	g.resize(n);
	grev.resize(n);
	s.resize(n, -1);
	e.resize(n, k);

	for (int i = 0; i < k; i++) {
		s[i] = i;
		e[i] = i;
	}
}

int add(int u, int v) {
	if (OO) {
		cout << "add " << u << " " << v << '\n';
	}
	if (s[u] >= e[v]) return 1;
	if (s[u] > s[v]) {
		while (s[u] - s[v] >= e[v] - s[u]) {
			if (OO) {
				cout << "add " << u << " " << v << " updates forward\n";
			}
			s[v] = (s[v] + e[v] + 1) / 2;
			for (const auto &i : g[v])
				if (add(v, i)) return 1;
		}
	}
	if (e[u] > e[v]) {
		while (e[u] - e[v] >= e[v] - s[u]) {
			if (OO) {
				cout << "add " << u << " " << v << " updates backward\n";
			}
			e[u] = (s[u] + e[u]) / 2;
			for (const auto &i : grev[u])
				if (add(i, u)) return 1;
		}
	}
	return 0;
}

void brute_dfs(vector<int> &vis, int v) {
	if (vis[v]) return;
	vis[v] = 1;
	for (const auto &i : g[v])
		brute_dfs(vis, i);
}

int brute() {
	vector<int> vis(n);
	for (int i = 0; i < k; i++) {
		for (auto &x : vis) x = 0;
		for (const auto &j : g[i])
			brute_dfs(vis, j);
		for (int j = 0; j <= i; j++)
			if (vis[j]) return 1;
	}
	return 0;
}

int add_teleporter(int u, int v) {
	if (OO) {
		cout << "current s: ";
		for (const auto &i : s) cout << i << " "; cout << '\n';
		cout << "current e: ";
		for (const auto &i : e) cout << i << " "; cout << '\n';
	}
	
	if (u < k && v < k) {
		return u >= v;
	}
	
	g[u].push_back(v);
	grev[v].push_back(u);
	int x = add(u, v);
	if (OOO) {
		int y = brute();
		if (x != y) {
			cout << "difference! " << x << " " << y << '\n';
			return 2;
		}
	}
	return x;
}

Compilation message (stderr)

game.cpp: In function 'int add_teleporter(int, int)':
game.cpp:83:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   83 |   for (const auto &i : s) cout << i << " "; cout << '\n';
      |   ^~~
game.cpp:83:45: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   83 |   for (const auto &i : s) cout << i << " "; cout << '\n';
      |                                             ^~~~
game.cpp:85:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   85 |   for (const auto &i : e) cout << i << " "; cout << '\n';
      |   ^~~
game.cpp:85:45: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   85 |   for (const auto &i : e) cout << i << " "; cout << '\n';
      |                                             ^~~~

• Subtask 1: 2 / 2
• Subtask 2: 10 / 10
• Subtask 3: 18 / 18
• Subtask 4: 30 / 30
• Subtask 5: 40 / 40