View Compilation Error

0_0_17084809_25622.cpp: In function 'void Insert(char*)':
0_0_17084809_25622.cpp:24:26: error: 'strlen' was not declared in this scope
     int len = strlen(word);
                          ^
0_0_17084809_25622.cpp: In function 'int Find(char*)':
0_0_17084809_25622.cpp:52:26: error: 'strlen' was not declared in this scope
     int len = strlen(word);
                          ^