Compilare: user.cpp:9:26: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] array<array<int,maxn-1>,1<<maxn-1> len; ^ user.cpp: In function ‘int main()’: user.cpp:22:14: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] int N = 1<<n-1; ^ user.cpp:27:13: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if (M&M-1 != 0) for (int M1 = M; M1 != 0; M1 &= M1-1) { ^ user.cpp:30:17: warning: suggest parentheses around arithmetic in operand of ‘^’ [-Wparentheses] int Mi = M^M1&-M1; ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.in", "r", stdin); ^ user.cpp:13:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.out", "w", stdout); ^