Compilare: user.cpp: In function ‘int main()’: user.cpp:35:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &N, &M); ^ user.cpp:37:26: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s + 1, M + 3, fin); ^ user.cpp:39:31: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(v[i] + 1, LG + 3, fin); ^ user.cpp:52:44: warning: ‘end’ may be used uninitialized in this function [-Wmaybe-uninitialized] int tot = lg + bst[std::min(i - lg, end - 1)]; ^