#include <iostream>
#include <ctime>

using namespace std;

static const int N {100000};

int main()
{
    srand(time(NULL));

    int i;
    int j;

    int id[N];
    int sz[N]; // Stores tree sizes

    int Ncount{}; // Counts the numbeer of new connections
    int Mcount{}; // Counts the number of all attempted connections

    for (i = 0; i < N; i++)
    {
        id[i] = i;
        sz[i] = 1;
    }

    while (Ncount < N - 1)
    {
        i = rand() % N;
        j = rand() % N;

        for (; i != id[i]; i = id[i])
            id[i] = id[id[i]];

        for (; j != id[j]; j = id[j])
            id[j] = id[id[j]];

        Mcount++;

        if (i == j) // Checks if i and j are connected
            continue;

        if (sz[i] < sz[j]) // Smaller tree will be
                           // connected to a bigger one
        {
            id[i] = j;
            sz[j] += sz[i];
        }
        else
        {
            id[j] = i;
            sz[i] += sz[j];
        }

        Ncount++;
    }

    cout << "Mcount: " << Mcount << endl;
    cout << "Ncount: " << Ncount << endl;

    return 0;
}

import random

N = 100000

idList = list(range(0, N))
sz = [1] * N

Ncount = 0
Mcount = 0

while Ncount < N - 1:

    i = random.randrange(0, N)
    j = random.randrange(0, N)

    while i is not idList[i]:
        idList[i] = idList[idList[i]]
        i = idList[i]

    while j is not idList[j]:
        idList[j] = idList[idList[j]]
        j = idList[j]

    Mcount += 1

    if i is j:
        continue

    if sz[i] < sz[j]:
        idList[i] = j
        sz[j] += sz[i]
    else:
        idList[j] = i
        sz[i] += sz[j]

    Ncount += 1

print("Mcount: ", Mcount)
print("Ncount: ", Ncount)

>>> x=100000
>>> y=100000
>>> x is y
False