Compilare: main.cpp: In function 'void dfs(int)': main.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edges[source].size(); i++) ~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:33:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^ main.cpp:38:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &parent); ^ main.cpp:50:14: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized] dfs(root); ^