Compilare: main.cpp: In function 'void bfs()': main.cpp:61:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < mat[p].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void prim()': main.cpp:128:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < mat[1].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp:157:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < mat[to].size(); ++i) { ~~^~~~~~~~~~~~~~~~ main.cpp: In member function 'bool comp::operator()(strD, strD)': main.cpp:44:5: warning: control reaches end of non-void function [-Wreturn-type] } ^