Compilare: user.cpp: In function ‘int main()’: user.cpp:27:15: warning: unused variable ‘x’ [-Wunused-variable] int t, i, j, x, y, n, k = 0; ^ user.cpp:27:18: warning: unused variable ‘y’ [-Wunused-variable] int t, i, j, x, y, n, k = 0; ^ user.cpp:27:24: warning: variable ‘k’ set but not used [-Wunused-but-set-variable] int t, i, j, x, y, n, k = 0; ^ user.cpp:24:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("streetcrypto.in", "r", stdin); ^ user.cpp:25:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("streetcrypto.out", "w", stdout); ^ user.cpp:35:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:37:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu", &v[i]); ^