Submission #736419

#	Time	Username	Problem	Language	Result	Execution time	Memory
736419		jk410	Thousands Islands (IOI22_islands)	C++17	24 / 100	45 ms	8268 KiB

islands

#include "islands.h"
#include <bits/stdc++.h>
using namespace std;
int n;
int edge[1000][1000];
int visited[1000];
int par[1000];
pair<int,int> dfs(int v) {
	visited[v] = 1;
	for (int i = 0; i < n; i++) {
		if (edge[v][i] == -1 || visited[i] == 2)
			continue;
		if (visited[i] == 1)
			return { v,i };
		par[i] = v;
		pair<int,int> tmp = dfs(i);
		if (tmp.first != -1)
			return tmp;
	}
	visited[v] = 2;
	return { -1,-1 };
}
variant<bool, vector<int>> find_journey(int _n, int m, vector<int> u, vector<int> v) {
	n = _n;
	memset(edge, -1, sizeof(edge));
	for (int i = 0; i < m; i += 2)
		edge[u[i]][v[i]] = i;
	pair<int,int> x = dfs(0);
	if (x.first == -1)
		return false;
	vector<int> cyc;
	cyc.push_back(x.second);
	for (int i = x.first;; i = par[i]) {
		cyc.push_back(i);
		if (i == x.second)
			break;
	}
	vector<int> p;
	for (int i = x.second;; i = par[i]) {
		p.push_back(i);
		if (!i)
			break;
	}
	vector<int> ret;
	for (int i = (int)p.size() - 1; i; i--)
		ret.push_back(edge[p[i]][p[i - 1]]);
	for (int i = (int)cyc.size() - 1; i; i--)
		ret.push_back(edge[cyc[i]][cyc[i - 1]]);
	for (int i = (int)cyc.size() - 1; i; i--)
		ret.push_back(edge[cyc[i]][cyc[i - 1]] + 1);
	for (int i = 1; i < (int)cyc.size(); i++)
		ret.push_back(edge[cyc[i]][cyc[i - 1]]);
	for (int i = 1; i < (int)cyc.size(); i++)
		ret.push_back(edge[cyc[i]][cyc[i - 1]] + 1);
	for (int i = 1; i < (int)p.size(); i++)
		ret.push_back(edge[p[i]][p[i - 1]]);
	return ret;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 21
• Subtask 4: 24 / 24
• Subtask 5: 0 / 45