View Compilation Error

0_0_22153144_21448.cpp: In function 'int query(int, int)':
0_0_22153144_21448.cpp:66:15: error: invalid types 'int[int]' for array subscript
     return r[a] < r[b] ? a : b;
               ^
0_0_22153144_21448.cpp:66:22: error: invalid types 'int[int]' for array subscript
     return r[a] < r[b] ? a : b;
                      ^