foo.cc: In function 'int main()':
foo.cc:12:22: error: 'mn1' was not declared in this scope; did you mean 'mn2'?
   12 |  for(int i=2;i<m;i++)mn1=min(mn1,a[i+1]-a[i]);
      |                      ^~~
      |                      mn2
foo.cc:14:18: error: 'mn1' was not declared in this scope; did you mean 'mn2'?
   14 |  cout<<min(mn2/2,mn1);
      |                  ^~~
      |                  mn2
foo.cc:8:10: warning: unused variable 'n1' [-Wunused-variable]
    8 |  int n,m,n1=Mx,mn2=-Mx;
      |          ^~

Found 10 testcases.
[Hydro](https://hydro.ac)提供评测服务