/in/foo.c: In function 'main':
/in/foo.c:10:2: warning: implicit declaration of function 'MoveLeft' [-Wimplicit-function-declaration]
  MoveLeft(n,a);
  ^~~~~~~~
/in/foo.c: At top level:
/in/foo.c:14:6: warning: conflicting types for 'MoveLeft'
 void MoveLeft(int n,int a[])
      ^~~~~~~~
/in/foo.c:10:2: note: previous implicit declaration of 'MoveLeft' was here
  MoveLeft(n,a);
  ^~~~~~~~