foo.cc: In function 'void qsort(int, int)':
foo.cc:19:5: error: expected 'while' before 'main'
   19 | int main()
      |     ^~~~
foo.cc:19:5: error: expected '(' before 'main'
   19 | int main()
      |     ^~~~
      |     (
foo.cc:19:5: error: 'main' was not declared in this scope
   19 | int main()
      |     ^~~~
foo.cc:19:11: error: expected ')' before '{' token
   19 | int main()
      |     ~~~~  ^
      |           )
   20 | {
      | ~          
foo.cc:19:11: error: expected ';' before '{' token
   19 | int main()
      |           ^
      |           ;
   20 | {
      | ~          
foo.cc:31:9: error: return-statement with a value, in function returning 'void' [-fpermissive]
   31 |  return 0;
      |         ^
foo.cc:32:1: error: expected '}' at end of input
   32 | }
      | ^
foo.cc:7:1: note: to match this '{'
    7 | {
      | ^

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