View Compilation Error

0_0_29329459_29256.cpp: In function 'void ma()':
0_0_29329459_29256.cpp:16:37: error: 'strlen' was not declared in this scope
  int ma_len = 1,raw_len = strlen(raw);
                                     ^
0_0_29329459_29256.cpp: In function 'int main()':
0_0_29329459_29256.cpp:44:24: error: 'strlen' was not declared in this scope
   int len_ = strlen(raw);
                        ^