Compilare: user.cpp: In function ‘int main()’: user.cpp:13:6: warning: unused variable ‘a’ [-Wunused-variable] int a, b, c; ^ user.cpp:13:9: warning: unused variable ‘b’ [-Wunused-variable] int a, b, c; ^ user.cpp:13:12: warning: unused variable ‘c’ [-Wunused-variable] int a, b, c; ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin); ^ user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.out","w",stdout); ^ user.cpp:18:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^