View Compilation Error

0_0_19033690_9129.cpp: In function 'bool cmp(const Data&, const Data&)':
0_0_19033690_9129.cpp:9:28: error: 'strcmp' was not declared in this scope
   return strcmp(d1.ID,d2.ID)<0?1:0;  
                            ^
0_0_19033690_9129.cpp: In function 'int main()':
0_0_19033690_9129.cpp:17:32: error: 'memset' was not declared in this scope
         memset(d,NULL,sizeof(d));  
                                ^