/in/foo.cc: In function 'int FindMax(int, int*)':
/in/foo.cc:15:9: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return num;
         ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:27:19: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<FindMax(n,b)<<endl;
                   ^