foo.cc: In function 'int read()':
foo.cc:10:16: error: 'ch' was not declared in this scope
  while(in>'9'||ch<'0')
                ^~
foo.cc:18:8: error: 'ch' was not declared in this scope
  while(ch>='0'&&ch<='9')
        ^~
foo.cc: In function 'int main()':
foo.cc:41:3: error: 'll' was not declared in this scope
   ll t1=0;
   ^~
foo.cc:41:3: note: suggested alternative: 'l'
   ll t1=0;
   ^~
   l
foo.cc:42:27: error: 't1' was not declared in this scope
   for(int j=l; j<=r; j++) t1+=abs(a[j]-a[mid]);
                           ^~
foo.cc:42:27: note: suggested alternative: 'tm'
   for(int j=l; j<=r; j++) t1+=abs(a[j]-a[mid]);
                           ^~
                           tm
foo.cc:43:8: error: 't1' was not declared in this scope
   tot+=t1;
        ^~
foo.cc:43:8: note: suggested alternative: 'tm'
   tot+=t1;
        ^~
        tm

[Hydro](https://hydro.ac)提供评测服务