Compilare: main.cpp: In function 'void bfs()': main.cpp:59:27: 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:81:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < mat[1].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp:109:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < mat[to].size(); ++i) { ~~^~~~~~~~~~~~~~~~