Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:17:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<adj[i].size(); ++j){ ^ user.cpp: In function ‘int main()’: user.cpp:41:34: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘std::vector<int>::size_type {aka unsigned int}’ [-Wformat=] printf("%lu ", cntr[i].size()); ^ user.cpp:42:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<cntr[i].size(); ++j) printf("%d ", cntr[i][j]); ^ user.cpp:25:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^