func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 100 + 10;   double dp[2][maxn][maxn];   double s[maxn][maxn], s2[maxn][maxn];   inline double S(int x1, int y1, int x2, int y2) {     return s[x2][y2] - s[x2][y1 - 1] - s[x1 - 1][y2] + s[x1 - 1][y1 - 1];   }   inline double S2(int x1, int y1, int x2, int y2) {     return s2[x2][y2] - s2[x1 - 1][y1 - 1];   }   int a[maxn];   int main() {     int n, k;     scanf( %d%d , &n, &k);     k = min(k, 1000);     for (int i = 1; i <= n; i++) scanf( %d , &a[i]);     for (int m = 1; m <= k; m++) {       for (int i = 1; i <= n + 1; i++)         for (int j = 1; j <= n + 1; j++)           s[i][j] =               s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1] + dp[(m + 1) % 2][i][j],           s2[i][j] = s2[i - 1][j - 1] + dp[(m + 1) % 2][i][j];       for (int i = 1; i <= n; i++)         for (int j = i + 1; j <= n; j++) {           double &d = dp[m % 2][i][j];           d = 0;           for (int x = 1; x <= i; x++)             d += S(x, j, x + j - i - 1, j) +                  (n - j + 1 - S2(x, x + j - i, x + n - j, x + n - i));           for (int x = i + 1; x <= j; x++) d += S(i, x, i, x + n - j);           int mul = (n - j + 1) * (n - j) / 2 + i * (i - 1) / 2 +                     (j - i) * (j - i - 1) / 2;           d += mul * dp[(m + 1) % 2][i][j];           d /= (n * (n + 1) / 2);         }     }     double ans = 0;     for (int i = 1; i <= n; i++)       for (int j = i + 1; j <= n; j++)         ans += (a[i] > a[j] ? (1 - dp[k % 2][i][j]) : dp[k % 2][i][j]);     printf( %.10f n , ans);   }   