Compilare: user.cpp: In function ‘void back(int, int, int, int, int)’: user.cpp:11:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( unu > Biti[Valoare].size() / 2 || zero > Biti[Valoare].size() / 2) return ; ^ user.cpp:11:74: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( unu > Biti[Valoare].size() / 2 || zero > Biti[Valoare].size() / 2) return ; ^ user.cpp:12:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (bit == Biti[Valoare].size() ) ^ user.cpp: In function ‘int main()’: user.cpp:23:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tractor.in", "r", stdin); ^ user.cpp:24:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tractor.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", &T); ^ user.cpp:35:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:38:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &A[i][j]); ^