Compilare: user.cpp: In function ‘int main()’: user.cpp:86:37: warning: value computed is not used [-Wunused-value] for(int j = m ; j >= 1 ; +--j) { ^ user.cpp:15:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bmatrix.in" , "r" , stdin); ^ user.cpp:16:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bmatrix.out" , "w" , stdout); ^ user.cpp:18:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &m); ^ user.cpp:20:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s" , mat[i] + 1); ^