Compilare: user.cpp: In function ‘int main()’: user.cpp:97:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < solution[fmask].size() ; ++i) ^ user.cpp:98:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0 ; j < solution[fmask][i].size() ; ++j) ^ user.cpp:24:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scara2.in" , "r" , stdin); ^ user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scara2.out" , "w" , stdout); ^ user.cpp:27:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &h); ^ user.cpp:28:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:29:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &m); ^ user.cpp:30:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &p); ^