View Compilation Error

0_0_32836246_6343.cpp: In function 'void Manacher()':
0_0_32836246_6343.cpp:32:43: error: 'lens' was not declared in this scope
         while(i - p[i] >= 0 && i + p[i] < lens && s[i + p[i]] == s[i - p[i]])
                                           ^