#include <iostream>
#include <vector>
 
int main() {
 
	// V = number of vertices
	// E = number of edges
	int V, E;
	int x, y, w;
	std::cin >> V >> E;
 	std::vector <std::vector <std::pair <int, int> > > graph_directed(V);
 	std::vector <std::vector <std::pair <int, int> > > graph_undirected(V);
 
	// assuming 0-based indexing of vertices
	for(int i = 0; i < E; i++) {
		std::cin >> x >> y >> w;
		graph_directed[x].push_back({y, w});	// adding a single edge in directed
 
		graph_undirected[x].push_back({y, w});
		graph_undirected[y].push_back({x, w});	// adding both the edges in undirected
	}
 
	// Printing graph (showing only undirected but the code is same for both)
	for(int i = 0; i < graph_undirected.size(); i++) {
		std::cout << i << ": ";
		for(int j = 0; j < graph_undirected[i].size(); j++)
			std::cout << "{" << graph_undirected[i][j].first << ", " << graph_undirected[i][j].second << "} ";
		std::cout << std::endl;
	}
	return 0;
}

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MyAzCjAgMSAxMAoxIDIgMTUKMCAyIDIw

3 3
0 1 10
1 2 15
0 2 20