View Compilation Error

0_0_14265016_28396.cpp: In member function 'void SuffixArray::add(char*)':
0_0_14265016_28396.cpp:58:42: error: 'x' was not declared in this scope
         for(int i = 0; i < 2 * len; i++) x[i] = y[i] = 0;
                                          ^
0_0_14265016_28396.cpp:58:49: error: 'y' was not declared in this scope
         for(int i = 0; i < 2 * len; i++) x[i] = y[i] = 0;
                                                 ^