View Compilation Error

0_0_23717598_15184.cpp:3:12: error: array bound is not an integer constant before ']' token
 int pre[MAX];
            ^
0_0_23717598_15184.cpp: In function 'void init(int)':
0_0_23717598_15184.cpp:6:2: error: 'pre' was not declared in this scope
  pre[i]=i;
  ^
0_0_23717598_15184.cpp: In function 'int find(int)':
0_0_23717598_15184.cpp:9:5: error: 'pre' was not declared in this scope
  if(pre[x]==x) return x;
     ^
0_0_23717598_15184.cpp:10:9: error: 'pre' was not declared in this scope
  return pre[x]=find(pre[x]);
         ^
0_0_23717598_15184.cpp: In function 'void unite(int, int)':
0_0_23717598_15184.cpp:16:2: error: 'pre' was not declared in this scope
  pre[x]=y; 
  ^