Disjoint set

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    //finding root of an element.
    static int root(ref int[] Arr,int i){
        while(Arr[ i ] != i)
        {
            Arr[ i ] = Arr[ Arr[ i ] ] ;
            i = Arr[ i ];
        }
        return i;
    }

    /*modified union function where we connect the elements by changing the root of one of the element */

    static void weightedUnion(ref int[] Arr,ref int[] size,int A,int B)
    {
        int root_A = root(ref Arr,A);
        int root_B = root(ref Arr,B);
        if(root_A==root_B) return;
        if(size[root_A] < size[root_B ])
        {
            Arr[ root_A ] = Arr[root_B];
            size[root_B] += size[root_A];
        }
        else
        {
            Arr[ root_B ] = Arr[root_A];
            size[root_A] += size[root_B];
        }

    }
    static bool find(ref int[] Arr, int A,int B){
        if( root(ref Arr,A)==root(ref Arr,B) )       //if A and B have same root,means they are connected.
            return true;
        else
            return false;
    }
    static void PrintArray(int[] arr,int n){
        for(int i=0;i<n;i++){
            Console.Write(arr[i]+",");
        }
        Console.WriteLine();
    }
    static Int64 journeyToMoon(int n, int[][] astronaut) {
        // Complete this function
        int totalCombinations=0;
        int[] countryArray = new int[n];
        int[] sizeArray = new int[n];
        for(int i=0;i<n;i++){
            countryArray[i] = i;
            sizeArray[i] = 1;
        }
        for(int i=0;i<astronaut.Length;i++){
            //if(!find(ref countryArray,astronaut[i][0],astronaut[i][1])){
            weightedUnion(ref countryArray,ref sizeArray,astronaut[i][0],astronaut[i][1]);
            PrintArray(countryArray,n);

        }

        Dictionary<int,List<int>> uniqueCountries = new Dictionary<int,List<int>>();
        for(int i=0;i<n;i++){
            if(!uniqueCountries.ContainsKey(countryArray[i])){
                List<int> tempList = new List<int>();
                tempList.Add(i);
                uniqueCountries.Add(countryArray[i],tempList);
            }else{
                List<int> tempList = uniqueCountries[countryArray[i]];
                tempList.Add(i);
            }
        }

        PrintArray(countryArray,n);
        PrintArray(sizeArray,n);
        //Console.WriteLine(countriesWithLength.Count);

        /*
        Int64 prevTotal = 0;
        foreach(var key in allCountries.Keys){
            if(!countries.ContainsKey(allCountries[key])){
                countries.Add(allCountries[key],allCountries[key].Count);
                if(prevTotal == 0){
                    prevTotal = allCountries[key].Count;
                }else{
                    totalCombinations+=(allCountries[key].Count*prevTotal);
                    prevTotal += allCountries[key].Count;
                }
            }
        }
        Console.WriteLine("Countries: " + countries.Count);
        */
        return totalCombinations;
    }

    static void Main(String[] args) {
        string[] tokens_n = Console.ReadLine().Split(' ');
        int n = Convert.ToInt32(tokens_n[0]);
        int p = Convert.ToInt32(tokens_n[1]);
        int[][] astronaut = new int[p][];
        for(int astronaut_i = 0; astronaut_i < p; astronaut_i++){
           string[] astronaut_temp = Console.ReadLine().Split(' ');
           astronaut[astronaut_i] = Array.ConvertAll(astronaut_temp,Int32.Parse);
        }
        Int64 result = journeyToMoon(n, astronaut);
        Console.WriteLine(result);
    }
}