Compilare: user.cpp: In function ‘int val()’: user.cpp:17:29: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses] ind = i ^ (1 << j) | (1 << u); ^ user.cpp:28:21: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] if (i == 1 << k - (1 << (k - 1))) return 0; ^ user.cpp: In function ‘int main()’: user.cpp:33:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coins.in", "r", stdin); ^ user.cpp:34:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coins.out", "w", stdout); ^ user.cpp:39:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:45:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &w[i]); ^