Compilare: main.cpp: In function 'int main()': main.cpp:66:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( a < components.size() && components[a][b] == -1 ) { ~~^~~~~~~~~~~~~~~~~~~ main.cpp:68:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( b == components[a].size() ) ~~^~~~~~~~~~~~~~~~~~~~~~~ main.cpp:71:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( a == components.size() ) { ~~^~~~~~~~~~~~~~~~~~~~