Compilare: user.cpp: In function ‘int main()’: user.cpp:21:25: warning: unused variable ‘ap’ [-Wunused-variable] int n, d, k = 0, i, ap, j, e, cn; ^ user.cpp:21:32: warning: unused variable ‘e’ [-Wunused-variable] int n, d, k = 0, i, ap, j, e, cn; ^ user.cpp:19:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapeze.in", "r", stdin); ^ user.cpp:20:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapeze.out", "w", stdout); ^ user.cpp:23:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^