Compilare: user.cpp: In function ‘int main()’: user.cpp:71:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (x = 0; x < a[nod].size(); x++) { ^ user.cpp:24:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1, "%d %d", &n, &m); ^ user.cpp:30:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1, "%d %d", &x, &y); ^