Submission #1042527

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042527		yanb	Thousands Islands (IOI22_islands)	C++17	Compilation error	0 ms	0 KiB

islands

#include <bits/stdc++.h>
	
using namespace std;
	
//#define int long long
#define pii pair<int, int>
	
variant<bool, vector<int>> n2(int n, int M, vector<int> U, vector<int> V) {
	vector<int> u0, u1;
	for (int i = 0; i < M; i++) {
		if (U[i]) u1.push_back(i);
		else u0.push_back(i);
	}
	
	if (u1.size() > 0 && u0.size() > 1) {
		vector<int> ans = {u0[0], u1[0], u0[1], u0[0], u1[0], u0[1]};
		return ans;
	} else {
		return false;
	}
}
	
void dfs(int n, int v, int p, vector<vector<vector<int>>> &g, vector<bool> &uu, vector<int> &ps) {
	if (uu[v]) return;
	uu[v] = 1;
	ps[v] = p;
	for (int u = 0; u < n; u++) {
		if (!g[v][u].empty()) {
			dfs(n, u, v, g, uu, ps);
		}
	}
}
	
variant<bool, vector<int>> undirected(int n, int M, vector<int> U, vector<int> V) {
	vector<vector<vector<int>>> g(n, vector<vector<int>>(n));
	for (int i = 0; i < M; i++) {
		g[U[i]][V[i]].push_back(i);
	}
	
	if (g[0].size() > 1) {
		/*int u = g[0][0].first, v = g[0][1].first;
		if (u == v) {
			vector<int> ans = {g[0][0].second, g[u][0].second, g[0][1].second, 
				g[0][0].second, g[u][0].second, g[0][1].second};
			return ans;
		}
		vector<int> ans = {g[0][0].second, g[u][0].second, g[0][1].second, g[v][0].second,
			g[u][0].second, g[0][0].second, g[v][0].second, g[0][1].second};
		return ans;*/
		return true;
	}
	
	vector<bool> uu(n);
	vector<int> p(n);
	dfs(n, 0, 0, g, uu, p);
	for (int i = 0; i < n; i++) {
		if (g[i].size() > 2 && uu[i]) {
			/*vector<int> ans, path;
			int v = i;
			while (v != 0) {
				path.push_back(v);
				v = p[v];
			}
			path.push_back(0);
			reverse(path.begin(), path.end());

			for (int i = 0; i < (int) path.size() - 1; i++) {
				ans.push_back(g[path[i]]);
			}*/

			return true;
		}
	}
	
	return false;
}
	
variant<bool, vector<int>> find_journey(int n, int M, vector<int> U, vector<int> V) {
	if (n == 2) return n2(n, M, U, V);
	return undirected(n, M, U, V);
}
	
#ifndef ONLINE_JUDGE
signed main() {
	variant<bool, vector<int>> ans = find_journey(5, 8, {0, 1, 1, 1, 2, 3, 4, 4}, 
		{4, 4, 2, 3, 1, 1, 1, 0});
	cout << get<bool>(ans) << "\n";
	//cout << get<vector<int>>(ans).size() << "\n";
}
#endif

Compilation message (stderr)

/usr/bin/ld: /tmp/cc4pJ5ZS.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccTnqgqS.o:islands.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status