Compilare: user.cpp: In function ‘void BFS(int, int*)’: user.cpp:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<mv[v].size();i++){ ~^~~~~~~~~~~~~ user.cpp:15:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,v; ^ user.cpp: In function ‘void niv(int)’: user.cpp:43:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<mv[v].size();i++){ ~^~~~~~~~~~~~~ user.cpp:34:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,v; ^ user.cpp: In function ‘int main()’: user.cpp:53:15: warning: unused variable ‘j’ [-Wunused-variable] int a,b,i,j,ans=2; ^