func_code_string: #include <bits/stdc++.h>   int a[2 * 1000010];   int main() {     int n, l, t, i, j, nn, k, left;     scanf( %d%d%d , &n, &l, &t);     nn = 2 * n;     for (i = 0; i < n; i++) scanf( %d , &a[i]);     for (i = n; i < nn; i++) a[i] = l + a[i - n];     k = 2 * t / l;     left = 2 * t - k * l;     double ans = 1.0 * (n - 1) * n * k;     for (i = 0, j = 0; i < n; i++) {       while (j < nn && a[j] - a[i] <= left) j++;       ans += j - 1 - i;     }     printf( %lf n , ans / 4);     return 0;   }   