View Compilation Error

0_0_32439520_13811.cpp: In function 'int main()':
0_0_32439520_13811.cpp:48:20: error: 'strlen' was not declared in this scope
   if (strlen(xiaoxi) > strlen(xiaoming))continue;
                    ^
0_0_32439520_13811.cpp:50:29: error: 'memset' was not declared in this scope
   memset(dic, 0, sizeof(dic));
                             ^
0_0_32439520_13811.cpp:61:32: error: 'strlen' was not declared in this scope
   for (i = 0; i < strlen(xiaoxi); i++)
                                ^