View Compilation Error

0_0_39837641_15648.cpp: In function 'int main()':
0_0_39837641_15648.cpp:17:13: error: 'merge_set' was not declared in this scope
   17 |             merge_set(A,B);
      |             ^~~~~~~~~
0_0_39837641_15648.cpp: In function 'void find_set(int)':
0_0_39837641_15648.cpp:31:13: error: third operand to the conditional operator is of type 'void', but the second operand is neither a throw-expression nor of type 'void'
   31 |     return x==root[x]?:find_set(root[x]);
      |            ~^~~~~~~~~
0_0_39837641_15648.cpp: In function 'void merge_set(int, int)':
0_0_39837641_15648.cpp:37:15: error: void value not ignored as it ought to be
   37 |     j=find_set(j);
      |       ~~~~~~~~^~~