#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdbool.h>

int main(int argc, char *argv[])
{
    const int n = 100;
    int perm[n];
    double e = 0;
    srand(time(NULL));
    for (int z = 0; z < 30; z++)
    {
        
        for (int j = 0; j < n; j++)
        {
            perm[j] = j;
        }
        
        int k = n;
        int idx;
        int count = 0;
        bool flag = 1;
        int N = 100000000;
        int j;
        for (int i = 0; i < N; i++)
        {
            j = rand() % (n - 1);
            
            int tmp = perm[j];
            perm[j] = perm[j + 1];
            perm[j + 1] = tmp;

            k += (perm[j] == j) + (perm[j + 1] == j + 1) - (perm[j] == j + 1) - (perm[j + 1] == j);
            
            if (k == 0 && flag)
            {
                flag = 0;
                idx = i;
            }
            else if (k == 0)
            {
                count++;
            }
        }

        e += (double)(N-idx) / count;
        printf("e = %f\n", (double)N / count);
    }
    printf("średnie e = %f\n", e / 30);
}