View Compilation Error

0_0_36786452_12230.cpp: In function 'void unite(int, int)':
0_0_36786452_12230.cpp:21:17: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
  int fa = find[a];
                 ^
0_0_36786452_12230.cpp:22:17: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
  int fb = find[b];
                 ^
0_0_36786452_12230.cpp: In function 'int kruskal()':
0_0_36786452_12230.cpp:31:17: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   if(find[e[i].u]!=find[e[i].v]){
                 ^
0_0_36786452_12230.cpp:31:31: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   if(find[e[i].u]!=find[e[i].v]){
                               ^