Compilare: user.cpp: In function ‘void get_per()’: user.cpp:65:21: warning: unused variable ‘ak’ [-Wunused-variable] int ak = 47; ^ user.cpp: In function ‘void solve()’: user.cpp:90:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k, x; ^ user.cpp:90:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, x; ^ user.cpp:90:18: warning: unused variable ‘x’ [-Wunused-variable] int i, j, k, x; ^ user.cpp: In function ‘void read()’: user.cpp:20:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spirala2.in", "r", stdin); ^ user.cpp:21:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &K); ^ user.cpp: In function ‘void write()’: user.cpp:130:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spirala2.out", "w", stdout); ^