Compilare: user.cpp: In function ‘int main()’: user.cpp:10:15: warning: unused variable ‘y’ [-Wunused-variable] int N, x, y, z; ^ user.cpp:10:18: warning: unused variable ‘z’ [-Wunused-variable] int N, x, y, z; ^ user.cpp:7:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("triplet.in", "r", stdin); ^ user.cpp:8:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("triplet.out", "w", stdout); ^ user.cpp:11:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^