Compilare: user.cpp: In function ‘void solve()’: user.cpp:98:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (config = 1; config < 1 << k; ++ config) ^ user.cpp: In function ‘void read()’: user.cpp:43:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gather.in", "r", stdin); ^ user.cpp:44:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u %u %u", &k, &n, &m); ^ user.cpp:49:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] w[i] = x; ^ user.cpp:54:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u %u %u %u", &e.x, &e.y, &e.c, &e.d); ^ user.cpp: In function ‘void write()’: user.cpp:110:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gather.out", "w", stdout); ^