View Compilation Error

0_0_35680078_311.cpp: In function 'int find22(int)':
0_0_35680078_311.cpp:73:11: error: 'pre' was not declared in this scope
  while(r!=pre[r])
           ^
0_0_35680078_311.cpp:78:8: error: 'pre' was not declared in this scope
  while(pre[i]!=r)
        ^