func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   double ans = 0;   void calc(vector<int> arr, int d, double p) {     if (d == 0) {       int tmp = 0;       for (int i = 0; i < n; ++i) {         for (int j = 0; j < i; ++j) {           if (arr[j] > arr[i]) {             tmp++;           }         }       }       ans += double(tmp) * p;       return;     }     for (int i = 0; i < n; ++i) {       for (int j = i; j < n; ++j) {         vector<int> xxx = arr;         reverse(xxx.begin() + min(i, j), xxx.begin() + max(i, j) + 1);         calc(xxx, d - 1, p / (n * (n + 1) / 2));       }     }   }   int main() {     int dep;     cin >> n >> dep;     vector<int> vec(n);     for (int i = 0; i < n; ++i) {       scanf( %d , &vec[i]);     }     calc(vec, dep, 1);     printf( %.10lf n , ans);     return 0;   }   