Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:24:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<graph[element].size() && !found;i++) ^ user.cpp: In function ‘int main()’: user.cpp:51:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<visited.size() && i<n;i++) ^