Compilare: main.cpp: In member function 'mat mat::operator*(const mat&)': main.cpp:14:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<m.size();i++){ ~^~~~~~~~~ main.cpp:16:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<aux.m[0].size();j++) ~^~~~~~~~~~~~~~~~ main.cpp:19:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<m.size();i++) ~^~~~~~~~~ main.cpp:20:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<aux.m[0].size();j++) ~^~~~~~~~~~~~~~~~ main.cpp:21:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<aux.m.size();k++) ~^~~~~~~~~~~~~