View Compilation Error

0_0_30619256_29122.cpp:5:5: error: expected unqualified-id before '[' token
 int [maxLen];
     ^
0_0_30619256_29122.cpp: In function 'void init(int)':
0_0_30619256_29122.cpp:10:9: error: 'pre' was not declared in this scope
         pre[i] = i;
         ^
0_0_30619256_29122.cpp: In function 'int find(int)':
0_0_30619256_29122.cpp:24:9: error: 'pre' was not declared in this scope
      if(pre[a] != a)
         ^
0_0_30619256_29122.cpp:24:13: error: 'a' was not declared in this scope
      if(pre[a] != a)
             ^
0_0_30619256_29122.cpp:29:12: error: 'pre' was not declared in this scope
     return pre[a];
            ^
0_0_30619256_29122.cpp:29:16: error: 'a' was not declared in this scope
     return pre[a];
                ^
0_0_30619256_29122.cpp: In function 'void un(int, int)':
0_0_30619256_29122.cpp:36:9: error: 'pre' was not declared in this scope
         pre[fa] = fb;
         ^