PCYCLE.cpp

/*

author: @karngyan
Team: BlundersPride

*/

#include<bits/stdc++.h>
using namespace std;
const int N = 1005;
int a[N];

int main()
{
	int n;
	cin >> n;
	// approach:
	// for each index we will find the cycle starting from that 
	// ignoring indices which are part of some other cycle

	// visited array denotes that if an index 
	// is visited i.e. its part of some cycle we
	// will not check a cycle starting from that index
	vector<bool> visited(n+1, false);

	// vector of vectors will contain all cycles we find
	vector< vector<int> > all_cycles;

 	for (int i = 1 ; i <= n ; ++i)
		cin >> a[i];

	for (int i = 1 ; i <= n ; ++i) {
        	if (!visited[a[i]]) {
		    vector<int> cycle;
		    cycle.push_back(i);
		    int next = a[i];
		    visited[i] = true;

		    while (next != i) {
			cycle.push_back(next);
			visited[next] = true;
			next = a[next];
		    }
		    cycle.push_back(next);
		    all_cycles.push_back(cycle);
		}
	}

	int k = all_cycles.size();
	
  	cout << k << "\n";
	
	for (auto cycle : all_cycles) {
		for (auto i : cycle)
			cout << i << " ";
		cout << "\n";
	}
    
	return 0;
}