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#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <queue>
using namespace std;
int INF = (1 << 30) - 1;
class Graph
{
private:
int n, m;
vector<vector<pair<int, int>>> adj_list_costs; //A vector with the neighbours of all the nodes and the cost of the edges between them
vector<vector<int>> adj_list; //A vector with the neighbours of all the nodes
public:
Graph(int nodes, int edges);
void add_edge_cost(int parent, int child, int cost);
void add_edge(int parent, int child);
int hamilton();
vector<int> dijkstra();
vector<int> euler_circuit();
};
Graph::Graph(int nodes_no, int edges_no) // Initiate the values of the graph
{
n = nodes_no;
m = edges_no;
adj_list_costs.resize(nodes_no + 1);
adj_list.resize(nodes_no + 1);
}
void Graph::add_edge_cost(int parent, int child, int cost) // Adding edges and their costs in the adjacency list
{
adj_list_costs[parent].push_back(make_pair(child, cost));
}
void Graph::add_edge(int parent, int child) // Adding edges in the adjacency list
{
adj_list[parent].push_back(child);
}
int Graph::hamilton() // Minimum Flow Cost Hamiltonian Cycle
{
int final_cost = INF; // The final cost of the Hamiltonian Cycle
int nodes_no = 1 << n;
vector<vector<int>> costs; // costs[i][j] of minimal costs between 0 and a node j that
// contains exactly the nodes used in binary representation of i
costs.resize(nodes_no);
for (int i = 0; i < nodes_no; i++)
for (int j = 0; j < n; j++)
costs[i].push_back(INF);
costs[1][0] = 0; // Let the cycle begin form the 0, so the cycle with only the node 0 has a cost of 0
for (int i = 0; i < nodes_no; i++) // i gives the nodes of the chain
for (int j = 0; j < n; j++)
if ((1 << j) & i) // Check if the node is a part of the chain described by i's binary representation
{
for (int k = 0; k < adj_list_costs[j].size(); k++) // Get through all the neighbours of the node
{
if (i & (1 << adj_list_costs[j][k].first)) // Check if the neighbour node is a part of the chain
{
// Actualise the minum cost - check if using the neighbouring node will get a better cost
costs[i][j] = min(costs[i][j], costs[i ^ (1 << j)][adj_list_costs[j][k].first] +
adj_list_costs[j][k].second);
}
}
}
for (int i = 0; i < adj_list_costs[0].size(); ++i)
final_cost = min(final_cost, costs[nodes_no - 1][adj_list_costs[0][i].first] +
adj_list_costs[0][i].second);
return final_cost;
}
vector<int> Graph::euler_circuit()
{
vector<int> euler_list;
for(int i=1; i<=n; i++) // Check the first condition for the graph to be eulerian: all its nodes must have an even number of neighbours
if (adj_list_costs[i].size() % 2 == 1)
{
euler_list.push_back(-1);
return euler_list;
}
vector<int> erased;
erased.resize(m);
for (int i = 1; i <= m; i++)
erased.push_back(0);
stack<int> aux;
aux.push(1); // Add the beginning node in the cycle
while (aux.empty() == false)
{
int node = aux.top();
if (adj_list_costs[node].empty() == false)
{
pair<int, int> edge = adj_list_costs[node].back(); // Take the edge and its orderd no so that i can erase it from the list
adj_list_costs[node].pop_back();
if (erased[edge.second] == 0) // Mark the erased edges
{
aux.push(edge.first);
erased[edge.second] = 1;
}
}
else
{
euler_list.push_back(node);
aux.pop();
}
}
return euler_list;
}
vector<int> Graph::dijkstra()
{
vector<int>distances(n + 1, 1000000);
priority_queue<pair<int, int>> pq; //with the use of a priority queue, I simulate a max heap(all the elements will pe in a descending order)
pq.push(make_pair(0, 1)); //and I'll always take the element from the tail
distances[1] = 0; //the cost of the soruce code is equal with 0
while (pq.empty() == false)
{
int source = pq.top().second;
//cout << source;
pq.pop();
for (size_t k = 0; k < adj_list_costs[source].size(); k++) //check whether the road through an intermidiate node is shorter than the actual one
{ //if so, add the new value in distances
pair<int, int> j = adj_list_costs[source][k];
int destination = j.first;
int cost = j.second;
//cout << destination << " " << cost << endl;
if (distances[source] + cost < distances[destination]) //if the value trhough an intermidiate node is shorter then the acual one, change the value
{
distances[destination] = distances[source] + cost;
//cout << distances[destination] << endl;
pq.push(make_pair(-distances[destination], destination)); // introduce the distance as negative integers, so the will be at the end of the pq
}
}
}
return distances;
}
int main()
{
/*
// Minimum Flow Cost Hamiltonian Cycle - https://www.infoarena.ro/problema/hamilton
int n, m;
ifstream in("hamilton.in");
ofstream out("hamilton.out");
in >> n >> m;
Graph g(n, m);
for (int i = 0; i < m; i++) // Reading each edge with its own cost
{
int parent, child, cost;
in >> parent >> child >> cost;
g.add_edge_cost(parent, child, cost);
}
int final_cost = g.hamilton(); // Check whether there are any Hamiltonian Cycles and return the minimal value found
if (final_cost != INF)
out << final_cost;
else
out << "Nu exista solutie";
in.close();
out.close();
*/
// Eulerian ciurcuit - https://www.infoarena.ro/problema/ciclueuler
/*int n, m;
ifstream in("ciclueuler.in");
ofstream out("ciclueuler.out");
in >> n >> m;
Graph g(n, m);
for (int i = 0; i < m; i++) // Reading each edge and adding its order
{
int parent, child;
in >> parent >> child;
g.add_edge_cost(parent, child, i+1);
g.add_edge_cost(child, parent, i+1);
}
in.close();
vector<int> euler_list = g.euler_circuit();
for (int i = 0; i < euler_list.size(); i++)
{
out << euler_list[i]<<" ";
}
out.close();*/
//Djikstra Algorithm - https://www.infoarena.ro/problema/dijkstra
int n, m;
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
in >> n >> m;
Graph g(n, m);
for (int i = 0; i < m; i++) // Reading each edge and adding its order
{
int parent, child, cost;
in >> parent >> child >> cost;
g.add_edge_cost(parent, child, cost);
}
in.close();
vector<int> result = g.dijkstra();
for (int i = 2; i <= n; i++)
if (result[i] == 1000000)
out << 0 << " ";
else out << result[i] << " ";
out.close();
return 0;
}