Compilare: main.cpp: In function 'int main()': main.cpp:21:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(i=0;i<M[j].size();i++) ~^~~~~~~~~~~~ main.cpp: In function 'void afisare(int)': main.cpp:30:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<M[j].size();i++) ~^~~~~~~~~~~~ main.cpp:34:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<M[M[j][i]].size();k++) ~^~~~~~~~~~~~~~~~~~