Compilare: user.cpp: In function ‘int main()’: user.cpp:27:15: warning: unused variable ‘x’ [-Wunused-variable] int n,k,i,x; ^ user.cpp:23:32: 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:24:34: 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:30:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:31:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) scanf("%d",&v[i]); ^