func_code_string: #include <bits/stdc++.h>   double p[1010][1010];   int a[1010];   int n, m;   int main() {     double t, ans;     int i, j, x, y;     scanf( %d%d , &n, &m);     for (i = 1; i <= n; i++) scanf( %d , &a[i]);     for (i = 1; i <= n; i++)       for (j = 1; j <= n; j++)         if (a[i] > a[j])           p[i][j] = 1;         else           p[i][j] = 0;     for (i = 1; i <= m; i++) {       scanf( %d%d , &x, &y);       p[x][y] = 0.5;       p[y][x] = 0.5;       for (j = 1; j <= n; j++)         if ((j != x) && (j != y)) {           t = (p[j][x] + p[j][y]) * 0.5;           p[j][x] = t;           p[x][j] = 1 - t;           p[j][y] = t;           p[y][j] = 1 - t;         }     }     ans = 0;     for (i = 1; i <= n - 1; i++)       for (j = i + 1; j <= n; j++) ans += p[i][j];     printf( %.10lf n , ans);     return 0;   }   