Language: C++

#include<cstdio>
using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namespce'
    2 | using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}
      |       ^~~~~~~~
a.cc: In function 'int read()':
a.cc:2:68: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
    2 | using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}
      |                                                                    ^~~
a.cc: In function 'int main()':
a.cc:2:233: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
    2 | using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}
      |                                                                                                                                                                                                                                         ^
a.cc:2:275: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
    2 | using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}
      |                                                                                                                                                                                                                                                                                   ^
a.cc:2:324: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
    2 | using namespce std;int n,a[200010];inline int read(){ register int ret=0;char c=getchar();while(c<'0'||c>'9')c=getchar();while(c>='0'&&c<='9')ret=(ret<<1)+(ret<<3)+(c^48),c=getchar();return ret;}int main(){n=read();for(register int i=1;i<=n;++i)a[i]=read();for(register int i=n;i>0;i-=2)printf("%d ",a[i]);for(register int i=(n&1)+1;i<=n;i+=2)printf("%d ",a[i]);return 0;}
      |                                                                                                                                                                                                                                                                                                                                    ^