Compilare: user.cpp: In function ‘void df(int)’: user.cpp:16:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[a].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:33:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d", &n, &m, &p); ^ user.cpp:38:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d", &a, &b); ^ user.cpp:43:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d", &a); ^