Compilare: main.cpp: In function 'void inmultire(matrix&, matrix&, matrix&)': main.cpp:20:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<A.size(); i++) ~^~~~~~~~~ main.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<B[0].size(); j++) ~^~~~~~~~~~~~ main.cpp:24:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<B.size(); k++) ~^~~~~~~~~