Submission #979800

#	Time	Username	Problem	Language	Result	Execution time	Memory
979800		Marcus	Swapping Cities (APIO20_swap)	C++17	6 / 100	89 ms	16060 KiB

swap

#include <swap.h>
#include <bits/stdc++.h>
using namespace std;
int n, m;
vector<vector<pair<int, int>>> adj;
vector<bool> visited;

bool cycle = false;
int gas = 0;
void dfs(int s, int v)
{
	if (visited[s]) return;
	visited[s] = true;
	for (auto u: adj[s])
	{
		if (visited[u.first] && u.first != v) cycle = true;
		gas = max(gas, u.second);
		dfs(u.first, s);
	}
}

namespace subtask2 {
	bool nodes = false;
	bool variation = false;
	bool execution = false;
	vector<pair<int, int>> edge;
}

void init(int n1, int m1, vector<int> v, vector<int> u, vector<int> w) {
	n = n1;
	m = m1;
	adj.resize(n);
	visited.resize(n);
	for (int i=0; i<m; i++)
	{
		adj[v[i]].push_back({u[i], w[i]});
		adj[u[i]].push_back({v[i], w[i]});
	}

	//confirmation for subtask2
	if (m == (n-1)) {subtask2::nodes = true;}
	for (auto s: v) {if (s != 0) {subtask2::variation = true;}}
	subtask2::execution = (subtask2::nodes && !(subtask2::variation));

	if (subtask2::execution) 
	{
		for (auto u: adj[0]) 
		{
			subtask2::edge.push_back({u.second, u.first});
		}
		sort(subtask2::edge.begin(), subtask2::edge.end());
		subtask2::edge.erase(subtask2::edge.begin()+3, subtask2::edge.end());
	}
}

int getMinimumFuelCapacity(int x, int y){
	if (subtask2::execution) 
	{
		if (n < 4) return -1;
		gas = max(adj[x][0].second, adj[y][0].second);
		for (auto &u: subtask2::edge)
		{
			if (u.second != x && u.second != y) {return max(u.first, gas);}
		}
	}
	dfs(1, 0);
	return (cycle ? gas : -1);
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27