func_code_string: #include <bits/stdc++.h>   using namespace std;   int vis[110000];   int st[110000], top;   int main() {     int n, m, i, j, k, x;     scanf( %d , &n);     if (n & 1) {       puts( -1 );       return 0;     }     st[++top] = 0;     x = n / 2;     while (x) {       st[++top] = x;       vis[x] = 1;       if (x + n >> 1 < n && !vis[x + n >> 1])         x = x + n >> 1;       else         x = x >> 1;     }     st[++top] = 0;     while (top) printf( %d  , st[top--]);     return 0;   }   