Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:48:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();++i) if(!used[v[x][i].w]) ^ user.cpp: In function ‘void DFS2(int)’: user.cpp:64:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=start[x];i<v[x].size();++i) if(gr[v[x][i].v] && used[v[x][i].w]) ^ user.cpp: In function ‘int main()’: user.cpp:112:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sol[i].size();++j) g<<sol[i][j]<<" "; ^