foo.cc: In function 'int FindMax(int*, int)':
foo.cc:5:13: warning: unused variable 'i' [-Wunused-variable]
    5 |         int i=0,max,r;
      |             ^
foo.cc:13:16: warning: 'r' may be used uninitialized [-Wmaybe-uninitialized]
   13 |         return r;
      |                ^
foo.cc:5:21: note: 'r' was declared here
    5 |         int i=0,max,r;
      |                     ^
foo.cc: In function 'int main()':
foo.cc:20:26: warning: 'r' may be used uninitialized [-Wmaybe-uninitialized]
   20 |         cout<<FindMax(a,n)<<endl;
      |                          ^
foo.cc:5:21: note: 'r' was declared here
    5 |         int i=0,max,r;
      |                     ^