Submission #168084

#	Time	Username	Problem	Language	Result	Execution time	Memory
168084		dolphingarlic	Toy Train (IOI17_train)	C++14	100 / 100	1039 ms	1528 KiB

train

#include "train.h"
#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
using namespace std;
 
vector<int> graph[5000];
bool arezou[5000], charging[5000], inactive[5000];
bool in_f_a[5000], in_f_b[5000];
int f_a, f_b, deg_in[5000];
 
vector<int> who_wins(vector<int> a, vector<int> r, vector<int> u, vector<int> v) {
	int n = a.size(), m = u.size();
	// Reverse edges
	FOR(i, 0, m) graph[v[i]].push_back(u[i]);
	FOR(i, 0, n) arezou[i] = a[i], charging[i] = r[i];
 
	vector<int> stations(n);
	FOR(i, 0, n) stations[i] = i;
	
	vector<int> res(n, 0);
	while (true) {
		for (int i : stations) {
			in_f_a[i] = in_f_b[i] = false;
			deg_in[i] = 0;
		}
		f_a = f_b = 0;
 
		FOR(i, 0, m) if (!inactive[u[i]] && !inactive[v[i]]) deg_in[u[i]]++;
 
		queue<int> q;
 
		for (int i : stations) if (charging[i]) {
			in_f_a[i] = true;
			f_a++;
			q.push(i);
		}
		while (q.size()) {
			int curr = q.front();
			q.pop();
			for (int i : graph[curr]) {
				deg_in[i]--;
				if (!in_f_a[i] && !inactive[i] && (arezou[i] || !deg_in[i])) {
					q.push(i);
					in_f_a[i] = true;
					f_a++;
				}
			}
		}
		if (f_a == stations.size()) {
			for (int i : stations) res[i] = true;
			break;
		}
 
		for (int i : stations) deg_in[i] = 0;
		FOR(i, 0, m) if (!inactive[u[i]] && !inactive[v[i]]) deg_in[u[i]]++;
 
		for (int i : stations) if (!in_f_a[i]) {
			in_f_b[i] = true;
			f_b++;
			q.push(i);
		}
		while (q.size()) {
			int curr = q.front();
			q.pop();
			for (int i : graph[curr]) {
				deg_in[i]--;
				if (!in_f_b[i] && !inactive[i] && (!arezou[i] || !deg_in[i])) {
					q.push(i);
					in_f_b[i] = true;
					f_b++;
				}
			}
		}
		if (f_b == stations.size()) break;
 
		vector<int> new_stations;
		for (int i : stations) {
			if (!in_f_b[i]) new_stations.push_back(i);
			else inactive[i] = true;
		}
		stations = new_stations;
	}
 
	return res;
}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:49:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (f_a == stations.size()) {
       ~~~~^~~~~~~~~~~~~~~~~~
train.cpp:74:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (f_b == stations.size()) break;
       ~~~~^~~~~~~~~~~~~~~~~~

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