Submission #45490

#	Time	Username	Problem	Language	Result	Execution time	Memory
45490		alenam0161	Toy Train (IOI17_train)	C++17	38 / 100	2058 ms	2620 KiB

train

#include "train.h"
#include <algorithm>
#include <iostream>
#include <cstdio>
#include <unordered_map>
#include <unordered_set>
#include <queue>
 
using namespace std;
const int N = 5e3 + 7;
int n, m;
 
unordered_set<int> R;
vector<int> g[N], g1[N];
vector<int> A;
unordered_set<int> cur;
unordered_set<int> rev(const unordered_set<int> &fi){
	cur.clear();
	for (int i = 0; i < n; ++i){
		if (fi.count(i) == 0)cur.insert(i);
	}
	return cur;
}
queue<int> q;
unordered_set<int> Fw(int w, const unordered_set<int> &fi){
	cur = fi;
	while (!q.empty())q.pop();
	for (int x : fi)
		q.push(x);
 
	while (!q.empty()){
		auto it = q.front(); q.pop();
		for (auto to : g1[it]){
			if (cur.count(to) == 1)
				continue;
 
			if (A[to] == w || all_of(g[to].begin(), g[to].end(), [&](const int &x){return cur.count(x) == 1; }))
			{
				cur.insert(to);
				q.push(to);
			} 
		}
	}
	return cur;
}
unordered_set<int> All;
unordered_set<int> merge(const unordered_set<int> &fi, const unordered_set<int> &se){
	All.clear();
	for (auto it : fi)
		if (se.count(it) == 1) All.insert(it);
	return All;
}
std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
	::n = a.size();
	::A = a;
	::m = u.size();
	vector<int> res;
	for (int i = 0; i < n; ++i)
		if (r[i] == 1) R.insert(i);
	for (int i = 0; i < m; ++i){
		g[u[i]].push_back(v[i]);
		g1[v[i]].push_back(u[i]);
	}
	unordered_set<int> M;
	while (true){
		auto R_ex = Fw(1, R);
		auto X = rev(R_ex);
		auto X_ex = Fw(0, X);
		M = merge(R, X_ex);
		for (auto it : M)
			R.erase(it);
		if (M.size() == 0){
			auto ans = vector<int>(n, 1);
			for (const auto &it : X_ex)
				ans[it] = 0;
			return ans;
		}
 
	}
	return res;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 0 / 51