Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<L[nod].size(); i++) ^ user.cpp: In function ‘void swap2()’: user.cpp:31:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[a]<=Niv[b]<=Niv[c]) ^ user.cpp:33:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[a]<=Niv[c]<=Niv[b]) ^ user.cpp:38:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[b]<=Niv[a]<=Niv[c]) ^ user.cpp:43:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[b]<=Niv[c]<=Niv[a]) ^ user.cpp:49:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[c]<=Niv[a]<=Niv[b]) ^ user.cpp:55:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] if(Niv[c]<=Niv[b]<=Niv[a]) ^