Compilare: main.cpp: In function 'void BFS(int)': main.cpp:19:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < w[x].size(); i ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:32:15: warning: unused variable 'i' [-Wunused-variable] int x, y, i, j; ^ main.cpp:32:18: warning: unused variable 'j' [-Wunused-variable] int x, y, i, j; ^