foo.cc:2:10: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
     main()
          ^
foo.cc: In function 'int main()':
foo.cc:4:9: error: 'printf' was not declared in this scope
         printf("\n original array:\n");
         ^~~~~~
foo.cc:4:9: note: suggested alternative: 'int'
         printf("\n original array:\n");
         ^~~~~~
         int
foo.cc:8:15: error: invalid conversion from 'int*' to 'int' [-fpermissive]
         {temp=a;
               ^
foo.cc:9:22: error: incompatible types in assignment of 'int' to 'int [5]'
             a=a[N-i-1];
                      ^

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