View Compilation Error

0_0_18222152_8943.cpp: In function 'bool check(double)':
0_0_18222152_8943.cpp:52:39: error: 'y' was not declared in this scope
         double dis = sqrt(len * len - y[i] * y[i]);
                                       ^
0_0_18222152_8943.cpp:53:20: error: 'x' was not declared in this scope
         l = max(l, x[i] - dis);
                    ^