Compilare: user.cpp: In function ‘void read()’: user.cpp:17:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < T ; ++i) ^ user.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < n ; ++i) ^ user.cpp:26:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < m; ++j) ^