Submission #731454

#	Time	Username	Problem	Language	Result	Execution time	Memory
731454		eneskav	Političari (COCI20_politicari)	C++17	70 / 70	17 ms	4204 KiB

politicari

#include <iostream>
#include <vector>
#include <cstring>
#define int long long
using namespace std;
#define fastio                        \
	ios_base::sync_with_stdio(false); \
	cin.tie(NULL);                    \
	cout.tie(NULL);
signed main()
{
	fastio;
  
	int n, k;
	cin >> n >> k;
	int a[n + 1][n + 1];
	for (int i = 1; i <= n; ++i)
		for (int j = 1; j <= n; ++j)
			cin >> a[i][j];
	if (k <= 2)
	{
		cout << k;
		return 0;
	}
	int vis[n + 1][n + 1];
	memset(vis, 0, sizeof(vis));
	int p = 0, c = 1;
	vector<int> v;
	v.push_back(1);
	a[c][p] = 2;
	int cycle = 0;
	for (int i = 1; i < k * 3; ++i)
	{
		int t = c;
		c = a[c][p];
		p = t;
		if (vis[c][p])
		{
			cycle = vis[c][p];
			v.pop_back();
			break;
		}
		vis[c][p] = i;
		v.push_back(c);
	}
	// print v
	/* for (auto i : v)
		cout << i << " ";
	cout << endl; */
	--cycle;
	// cout << "cycle " << cycle << endl;
	// cout << "cycle length " << v.size() - cycle << endl;
	if (k < v.size())
	{
		cout << v[k - 1];
		return 0;
	}
	// cout << v[((k - cycle) - 1) % (v.size() - cycle)];
	//  the code above is wrong, it should be like this
	cout << v[(k - cycle - 1) % (v.size() - cycle) + cycle];
	return 0;
}

Compilation message (stderr)

politicari.cpp: In function 'int main()':
politicari.cpp:53:8: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |  if (k < v.size())
      |      ~~^~~~~~~~~~

• Subtask 1: 70 / 70