Compilare: user.cpp: In function ‘void df(int, long long int)’: user.cpp:17:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[v].size(); i ++) { ^ user.cpp: In function ‘int main()’: user.cpp:26:54: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d %d %d", &n, &m, &start, &finish); ^ user.cpp:28:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%lld", &c[i]); ^ user.cpp:32:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", &x, &y); ^