Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:24:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<offers.size (); i++) ^ user.cpp:27:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<offers.size (); j++) ^ user.cpp: In function ‘int main()’: user.cpp:43:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("invtree.in", "r", stdin); ^ user.cpp:44:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("invtree.out", "w", stdout); ^ user.cpp:46:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &H); ^ user.cpp:50:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &x, &y, &z); ^