Compilare: user.cpp: In function ‘int main()’: user.cpp:95:57: warning: right operand of comma operator has no effect [-Wunused-value] st = 0, dr = min (X2 - X1 + 1, Y2 - Y1 + 1), mid; ^ user.cpp: In function ‘void num(int&)’: user.cpp:29:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, DIM, stdin); ^ user.cpp:38:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, DIM, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:46:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("matrice3.in" ,"r", stdin ); ^ user.cpp:47:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("matrice3.out","w", stdout); ^ user.cpp:49:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &N, &M, &Q); ^ user.cpp:51:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", A[i] + 1); ^ user.cpp:69:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, DIM, stdin); ^