Compilare: user.cpp: In function ‘void bfs(long int)’: user.cpp:31:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i = 0 ; i < adj_mat[t].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:53:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%li %li %li", &N, &M, &S); ^ user.cpp:58:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%lu %lu", &a, &b); ^