Untitled

#include <bits/stdc++.h>
using namespace std;

// Stores the parent of each vertex
int parent[1000000];

// Function to find the topmost
// parent of vertex a
int root(int a)
{
	// If current vertex is
	// the topmost vertex
	if (a == parent[a]) {
		return a;
	}

	// Otherwise, set topmost vertex of
	// its parent as its topmost vertex
	return parent[a] = root(parent[a]);
}

// Function to connect the component
// having vertex a with the component
// having vertex b
void connect(int a, int b)
{
	// Connect edges
	a = root(a);
	b = root(b);

	if (a != b) {
		parent[b] = a;
	}
}

// Function to find unique top most parents
void connectedComponents(int n)
{
	set<int> s;

	// Traverse all vertices
	for (int i = 0; i < n; i++) {

		// Insert all topmost
		// vertices obtained
		s.insert(root(parent[i]));
	}

	// Print count of connected components
	cout << s.size() << '\n';
}

// Function to print answer
void printAnswer(int N,vector<vector<int> > edges)
{

	// Setting parent to itself
	for (int i = 0; i <= N; i++) {
		parent[i] = i;
	}

	// Traverse all edges
	for (int i = 0; i < edges.size(); i++) {
		connect(edges[i][0], edges[i][1]);
	}

	// Print answer
	connectedComponents(N);
}

// Driver Code
int main()
{
	// Given N
	int N = 8;

	// Given edges
	vector<vector<int> > edges = {
		{ 1, 0 }, { 0, 2 }, { 5, 3 }, { 3, 4 }, { 6, 7 }
	};

	// Function call
	printAnswer(N, edges);

	return 0;
}