Disjoint Set Union Using Rank

#Rank Base

#include<bits/stdc++.h>

#define N 10001

using namespace std;

int parent[N+1];

int finds(int x)

{

    if(parent[x] < 0)

        return x;

    return parent[x] = finds(parent[x]);

}

void unions(int a, int b)

{

    int u = finds(a);

    int v = finds(b);

    if(u == v)

        cout << "They are already Friends." << "\n";

    else

    {

        if((parent[u] == parent[v]) || (parent[u] < parent[v]))

        {

            parent[u] += parent[v];

            parent[v] = u;

        }

        else

        {

            parent[v] += parent[u];

            parent[u] = v;

        }

        cout << a << " and " << b << " They are now Friends." << "\n";

    }

}

int main()

{

    int n, i, t, x, y;

    cout << "Enter Node Number :: ";

    cin >> n;

    for(i=1; i<=n; i++)

        parent[i] = -1;

    cout << "\nEnter Union Operation Number :: ";

    cin >> t;

    cout << "\nEnter Two Node For Union Operation " << t << " Times :: " << "\n";

    for(i=1; i<=t; i++)

    {

        cin >> x >> y;

        unions(x, y);

    }

    cout << "\n";

    for(i=1; i<=n; i++)

    {

        if(parent[i] < 0)

            cout << "Node " << i << " Parent itself." << "\n";

        else

            cout << "Node " << i << " parent is " << parent[i] << "\n";

    }

    return 0;

}