Compilare: user.cpp: In function ‘bool primetest(int)’: user.cpp:19:23: warning: unused variable ‘p5’ [-Wunused-variable] int p1, p2, p3, p4, p5; ^ user.cpp: In function ‘int main()’: user.cpp:36:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:38:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &x); ^