Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:33:39: 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:69:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<visited.size(); i++) ^ user.cpp:72:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<visited.size();i++) ^