Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:44:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<vertices[start_node].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:65:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i < answer.size(); i++) ^ user.cpp: In function ‘void read()’: user.cpp:21:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(iFile, "%d %d", &nodes, &edges); ^ user.cpp:23:47: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(iFile, "%d %d", &source, &destination); ^ user.cpp:31:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(iFile, "%d %d", &source, &destination); ^