Compilare: user.cpp: In function ‘int main()’: user.cpp:30:6: warning: unused variable ‘x’ [-Wunused-variable] int x, y; ^ user.cpp:30:9: warning: unused variable ‘y’ [-Wunused-variable] int x, y; ^ user.cpp:32:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.in","r",stdin); ^ user.cpp:33:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.out","w",stdout); ^ user.cpp:34:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &k); ^ user.cpp:36:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^